Chapter 10 Scientific Mapping in New York before 1860

This chapter discusses the origin and development in New York of what became known in the nineteenth and early twentieth centuries as “scientific mapping.” As has already been seen, the meaning of this term has changed over time. The various types of scientific mapping all derive from a generalized Western cartographic tradition, which originated in ancient Greece and Rome, and was greatly refined and elaborated in Europe after the Renaissance. Characteristic features of this tradition include the use of a uniform scale, the determination of locations by longitude and latitude, the use of mathematical projections to portray the surface of the globe on a flat sheet of paper, and the use of standardized symbols to represent features on the surface of the earth.

The striving for “accuracy” is characteristic of all types of scientific mapping. The underlying ideal is that a map should somehow resemble a miniature “mirror image” or a photograph of the earth’s surface. In the maps we have so far considered, efforts to achieve this ideal focused on the critical evaluation of sources. Efforts were made to determine latitudes (and at least some longitudes) astronomically. Distances between locations were measured by pacing, by the use of chains, or by odometers. Filling in of details was done by eye and hand. Maps of large areas, were usually made by combining maps and reducing them to a uniform scale. In some cases, measurements were adjusted to assure that maps were based on a common projection.

This procedure of putting together maps by collation and introducing corrections as new data came in was reasonably successful. As we have seen, the best maps became progressively more detailed and accurate between 1750 and 1802, and they thus became better at serving the pragmatic and utilitarian purposes for which they were designed. However, this procedure had serious weaknesses. It relied too much on the judgment of the individual mapmaker in selecting and correcting materials. It was often impossible for the cartographer or map user to be certain exactly how accurate a particular detail or location was. There was no easy and systematic way to find and correct errors. If a cartographer wanted to verify a particular detail, he had to check it himself or measure its location himself, or else send out someone he trusted to do the job for him.

As far back as the end of the seventeenth century, it was widely recognized that geometric triangulation was a way to remedy these problems and to produce more accurate maps. In theory, triangulation is simple enough. It involves carefully measuring one or more “baselines,” and then using precision optical instruments (such as theodolites or transits) to measure angles from each end of a baseline to known locations. In this way a network of triangles could be established, and, using trigonometry, distances could be measured. The accuracy of distances and locations could be assured by measuring from two baselines and checking for differences in measurements. Specific locations within this network of triangles could then be located by subtrianglation. It is easiest to grasp how this procedure works by looking at an example, such as that shown below in 10.4.

While this procedure was fairly simple in theory, it was not so easy to carry out in practice. It required expensive instruments, considerable time and labor, and practitioners with skill in astronomy and trigonometry. Creating sight lines in heavily forested areas often required chopping down large numbers of trees. The first trigonometrical survey of a large area was started in France at the end of the seventeenth century. By the end of the eighteenth century, similar surveys were underway in Great Britain, Switzerland, parts of Germany, and other European states. Throughout the eighteenth and nineteenth centuries, improvements in instruments along with new developments in astronomy and mathematics slowly raised the standards of these surveys.

The idea of conducting a systematic survey using triangulation in North America was not new. It had been proposed by Samuel Holland in the years following the French and Indian War. The idea was also raised several times in the years between 1784 and 1807, but nothing came of these early proposals. The immensity of the American landscape and its heavy forest cover discouraged efforts at large-scale surveying. Aside from issues of expense, the new nation lacked surveyors with sufficient expertise to conduct surveys according to the best European standards. Only with the immigration of the Swiss surveyor and scientist Ferdinand Rudolf Hassler in 1805 was there anyone in the United States really capable of conducting such a survey, and it was only after 1832 that Hassler was able to begin surveying on a large scale.

Ferdinand Rudolf Hassler and the U.S. Coast Survey

The key in the introduction of “scientific mapping” in the United States was Ferdinand Rudolf Hassler (1770-1843).[1] Hassler was born in German-speaking Switzerland, and educated primarily in Bern. The most important influence on Hassler’s career was Johann Georg Tralles, under whom he studied mathematics and geodesy. Hassler worked with Tralles on the survey of Switzerland in the years after 1791—using the most advanced methods of scientific mapping available at that time. In 1805, Hassler immigrated to the United States in part to escape restrictions on scientific activities under the Napoleonic occupation of Switzerland.[2]

10.1. Ferdinand Rudolf Hassler. NOAA Central Library.

Hassler’s influence on American science goes far beyond the boundaries of New York. He organized the United States Coast Survey, taught surveying to a generation of military engineers at West Point, played a critical role in the establishment of standardized weights and measures in the United States, and generally helped establish professional science in this country.

Although Hassler was a of national importance, much of his life was spent in New York, and most of his surveying was done in the vicinity of New York City.

It is no exaggeration to say that Hassler completely outclassed all previous surveyors and geodicists in early nineteenth-century America, including such luminaries as Andrew Ellicott and Simeon De Witt. This will become apparent as we review Hassler’s activities.

Almost immediately upon his arrival in the United States, Hassler started looking for a position in which he could employ his skills in astronomy and surveying. In 1806, he was hired by the Corporation of New York to conduct a survey of Manhattan and connect it through triangulation with Albany. A combination of illness on Hassler’s part and a change of administration in New York City caused this project to be abandoned.[3]

As early as the end of 1805, Hassler started attending meetings of the American Philosophical Society in Philadelphia. (He was elected a member on April 17, 1807.) Robert Patterson and John Vaughn brought him to the attention of President Thomas Jefferson, who was also a member of the society. Jefferson was interested in promoting a survey of the coast, and both he and his Swiss Secretary of the Treasury, Albert Gallatin, thought that Hassler might be able to contribute to it. In 1807, on the recommendation of President Jefferson, Congress passed a law authorizing a survey of the coast.[4]

On March 25, 1807, Gallatin issued a circular letter calling for proposals on the best way to implement a coast survey. Hassler’s proposal was selected, and he was chosen to head the survey. Following its rapid establishment, the Coast Survey encountered the first of a long series of problems and delays, which plagued it and Hassler for the rest of his life. Initially, the start of Coast Survey operations were delayed by the Embargo and other tensions leading up to the War of 1812.

Between 1809 and 1811 Hassler was employed at West Point and at Union College. At West Point, he taught mathematics and began writing a textbook on analytic trigonometry. Thus, he began the important task of training a new generation in up-to-date methods of surveying, astronomy, and mathematics. At that time, he made a considerable impression on Colonel Joseph Gardner Swift (the first graduate of West Point), who was head of the academy at that time. Swift became a life-long friend and supporter of Hassler, and (as seen in chapter 8), Swift also soon became an important in military cartography in his own right.

Finally, in August 1811, Hassler was sent to London to acquire the specialized instruments needed to carry out the survey. Most of these had to be made to order, and Hassler succeeded in acquiring an impressive collection of chronometers, telescopes, micrometers, and (most famously) a two-foot theodolite constructed by the famous London instrument maker Edward Troughton. Hassler’s work was delayed by the outbreak of the War of 1812, and he was not able to return to the United States until 1815.

10.2. Hassler’s “Great Theodolite” housed in a tent. NOAA Central Library.

After almost ten years of preparation and frustrating waiting, Hassler was finally able to begin work. He returned to the New York area, measured two baselines in New Jersey and on Western Long Island, and conducted an initial triangulation from them.

After this promising beginning, his work came to an abrupt halt. A storm, which had been brewing in Congress for some time, broke over Hassler’s head in 1818. Congressmen and others were frustrated by the lack of concrete results from the Coast Survey, and their frustrations were compounded by Hassler’s foreign origins and his peculiar personality. Hassler was conscientious, hard working, and intellectually brilliant. But he could also be vain, confrontational, and eccentric.

The upshot of this situation was that on April 18, 1818, Congress passed a law requiring that only officers of the army and navy could be employed by the survey, which effectively excluded Hassler. The most articulate upholder of the idea that the military was best suited to conduct these surveys was Colonel Isaac Roberdeau, head of the Army Topographic Engineers, who has already been encountered in the previous chapter.[5] Roberdeau maintained that the military engineers not only had the necessary qualifications to carry out a coastal survey, but that an adequate survey could be done less expensively by omitting the difficult large-scale triangulation advocated by Hassler, and by relying instead on astronomical observations to fix the locations of individual points, and then using them to tie together more limited surveys. Although some surveying of individual harbors was done by the military in the years between 1818 and 1832, it finally became apparent that the army and navy were not in fact able to carry out a comprehensive survey of the coasts.

With the Coast Survey was suspended, Hassler had to look elsewhere for employment. As far as the mapping of New York is concerned, the most important of his activities during the years when the Coast Survey was in suspension was the boundary survey between the United States and British North America (later Canada). This survey came about as a result of the treaty of Ghent, which ended the War of 1812, and set up a mechanism for surveying the disputed boundary between the two countries.[6] Hassler was appointed by President Monroe in 1818 as one of the astronomers on the American side of the survey. His involvement in this project, which lasted only about a year, was limited to resurveying the Canadian boundary with Vermont and New York, which runs along the 45th parallel of latitude.

Hassler’s involvement in this seemingly straightforward project speaks volumes about the development of geodesy and surveying in New York. It will be recalled that this line, known as the Collins-Valentine line, had been surveyed by the British shortly before the Revolution. The team of surveyors that originally surveyed this line, which included Claude Joseph Sauthier, was reasonably competent by the standards of the time.

On the new survey, Hassler worked with John Louis Tiarks, a surveyor born and educated in Germany, who represented the British. Hassler and Tiarks discovered that the Collins-Valentine line deviated appreciably from the 45th parallel. Most dramatically, they determined that the 45th parallel at Rouse’s Point (on northern Lake Champlain) was nearly one mile further south than had been thought previously, which dismayed the Americans, who had constructed a major fort on what was now determined to be Canadian soil (Fort Montgomery also known as “Fort Blunder”). In fact, the entire boundary line was shown to wander back and forth across the 45th parallel, thereby complicating boundary negotiations, which were not finally settled until the Webster-Ashburton Treaty was ratified in 1842. The final treaty reaffirmed the original Collins-Valentine line as the boundary between Canada and New York, even though it was not geodetically correct. [7]

The most revealing comments about the techniques used by Hassler and Tiarks come from Andrew Ellicott, who was also a member of the American team on the boundary survey. On July 24, 1819, he wrote to his wife:

Since I came here, I have had much conversation with my old friend, and astronomical companion S. De Witt, surveyor gen[eral] of this State, who is a man of science, and a good practical astronomer; he informs me, that he spent several days with Mr. Hassler and the British astronomer on the boundary last summer; but could not entirely comprehend the nature of their operations, and (between ourselves), he assured me that as far as he could comprehend them, they appeared better calculated for expense than accuracy.

A week later Ellicott added in another letter to his wife:

As to our business I can say nothing at present, and candidly confess that I do not yet comprehend the method pursued by the British astronomer and Mr. Hastler [sic], it is different from anything I have yet seen or heard of, not more than one observation in ten can possibly be applied to the boundary—those that can are probably good, but their mode of calculation is laborious in the extreme.[8]

These remarks illustrate the huge gulf between Hassler and his American predecessors. As shown in Chapter 8, Andrew Ellicott was arguably the most capable American surveyor of his generation, and Simeon De Witt was not far behind him. The comments by Ellicott and De Witt about the incomprehensibility of Hassler’s methods, as well as their unnecessary labor and expense, do much to explain the controversy and difficulties that plagued Hassler throughout his career. If America’s elite surveyors took this attitude, it is hardly surprising that congressmen and others without a strong background in astronomy or cartography expressed frustration at the expense and slowness of Hassler’s work.

The years between 1820 and 1830 were the most difficult in Hassler’s career. He had to scratch and scrabble to earn a meager living for himself and his sizable family. For a while, he taught at an academy in Jamaica, Long Island. He wrote text books on mathematics, and published an important compilation of papers relating to the activities of the Coast Survey.[9] He tried his hand at farming in Jefferson County, and attempted unsuccessfully to find a position teaching at a university. Finally, in 1829, he was reduced to working as gauger in the New York City Custom House.

Hassler’s fortunes finally turned around when, in1830, President Andrew Jackson appointed him U.S. Superintendent of Weights and Measures. Although Jackson is not usually thought of as a patron of intellectual activities, he seems to have liked and respected Hassler, and supported him against opposition on several occasions. In his important role as Superintendent, Hassler did a great deal to standardize weights and measures in the United States. He thereby effectively put an end to such problems as the lack of a uniform standard for the length of the foot, which, as has been seen, caused difficulties for Joseph Ellicott.

Hassler continued as Superintendent of Weights and Measures until his death in 1844. After 1832, he held this position concurrently with Superintendent of the Coast Survey. The Coast Survey was revived by Congress in that year after much debate, and Jackson was again responsible for reappointing Hassler to his old position. It was in the final years of his life, between 1832 and 1844, that Hassler made his most important contributions to the mapping of New York, and of the nation.

In spite of these successes, Hassler’s final years continued to be marked by Congressional investigations and other battles with opponents who complained of the slow pace and high cost of the Coast Survey. Hassler was convinced that his critics were ignorant fools, but his own prickly and eccentric personality continued to undermine his work. A number of amusing stories were in circulation about his strange behavior. One of these, which has been retold repeatedly, is worth repeating once again because it is so revealing of Hassler’s character. According to this story, sometime around 1836 Hassler got into a dispute about his salary with his superior, Levy Woodbury, Secretary of the Treasury under Jackson. This disagreement was eventually referred to the president himself, who reportedly had this conversation with Hassler:

“So, Mr. Hassler, it appears the Secretary and you cannot agree about this matter” remarked Jackson, when Hassler had stated his case in his usual emphatic style. “No, Sir, ve can’t.” “Well, how much do you really think you ought to have?” “Six thousand dollars, Sir.” “Why, Mr. Hassler, that is as much as Mr. Woodbury, my Secretary of the Treasury, himself receives. “Mr. Voodbury!” declared Hassler, rising from his chair, “There are plenty of Voodburys, plenty of Everybodys who can be made the Secretary of the Treasury.” “But,” he said, pointing his forefinger toward himself, “there is only one, one Hassler for the head of the Coast Survey.”[10]

Hassler got his raise—once again demonstrating Jackson’s support for this unusual bureaucrat.

Coast Survey Mapping in New York, 1832-1844

After his reappointment as Superintendent of the Coast Survey in 1832, Hassler picked up where he had left off in 1818. He returned to New the New York City area, and proceeded to lay out a new base line on Fire Island, which effectively became the starting point for all subsequent work by the Coast Survey ( 10.4).

It is worth describing how Hassler went about constructing the Fire Island base line, if only because it illustrates Hassler’s fetish for precision. It was laid out on the beach, and reached a length of 4,058.9870 meters. It was carefully measured by using an assemblage of four iron bars, each of which was two meters long. Elaborate precautions were taken to ensure that the bars were lined up straight, and that there was no gap between them. This operation had to be repeated approximately 1800 times. Measures were taken to insulate the bars to prevent their expansion and contraction, and the temperature of the bars at each setup was measured. Hassler and his assistants afterwards calculated the amount of expansion or contraction for each setup.[11]

10.3. Hassler’s Camp on Long Island. NOAA Central Library.

Hassler’s Fire Island baseline was constructed in a more painstaking manner than the two preliminary baselines he had measured in 1817. Once this baseline was measured, he and his assistants used theodolites to create a network of triangles, part of which can be seen in 10.4. The longitudes and latitudes of the points used as vertexes of these triangles were checked astronomically, and the accuracy of the measurements was further checked by trigonometrical measurements from neighboring triangles.

10.4. Triangulations from Long Island baseline. Coast Survey Annual Report. Stony Brook University Library.

The overall accuracy of Hassler’s surveys is illustrated by his use of triangulation from the Fire Island baseline to recalculate the length of the baselines he had measured in 1817. It was found that “the difference between the measured and computed lengths of these lines was in one case less than a foot, and in the other about four inches; the bases themselves were 5.9 and 4.8 miles long.”[12]

Once this network of large triangles (the “preliminary triangulation”) had advanced beyond a certain point, Hassler and his assistants started subdividing these triangles into smaller triangles (the “secondary triangulation.”). Sometimes these were further subdivided in a tertiary triangulation. Once a sufficiently fine network of triangles was established, his assistants were able to begin detailed mapping using plane tables. Plane tables appear not to have been used extensively in the United States prior to Hassler, although they were occasionally used by British surveyors like Samuel Holland and John Montresor prior to the Revolution. Plane table surveying also operated on the principle of measuring distances by triangulation.

Hassler’s obsession with accuracy meant that he had to pay more attention to the problem of map projection. For him, a simple conic projection, such as had been used by Simeon De Witt and others for New York, distorted distances and shapes too much to meet his exacting standards. To meet the need to decrease these distortions, he invented the more complex polyconic projection, which minimized the distortions, although it did not entirely eliminate them. In the final chapter of this book, we will take up the theme of how New York’s mapmakers have struggled to produce ever more accurate projections of the earth’s sphere on paper.

Beginning in 1834, Hassler’s assistants began producing a series of large-scale topographic maps of coastal areas. The first was drawn by Charles Renard, and covered part of the south shore of Long Island at a scale of 1:10,000. The legislation authorizing the Coast Survey called for mapping areas as much as twenty leagues (sixty miles) from the shore. The rationale for this was that the coastal charts were to serve both for navigation and for the military defense of the coast. Consequently, all parts of Long Island were mapped, as well as many other areas that were well away from navigable waters, including the Hudson River valley. The areas on the immediate coast were mapped at a scale of 1:10,000; those further inland at a scale of 1:20,000.

By Hassler’s death in 1844, all of Long Island had been mapped in manuscript, as well as the five boroughs of modern New York City, and much of the lower Hudson River Valley. Later in the nineteenth century, these manuscript surveys were extended to include Lake Champlain and the Hudson River as far north as Albany.

For the limited areas that they cover, these manuscript maps constitute an invaluable resource for historical research. Because most of them were never published, they are relatively little known. For a long time, they were in possession of the Coast Survey and its successor agencies (the U.S. Coast and Geodetic Survey and, most recently, The National Oceanic and Atmospheric Administration or NOAA). Some regional libraries have copies of these maps, which were sold by NOAA. Several years ago, they were transferred from NOAA to the National Archives, where they can now be consulted. Most recently, digital copies of these maps have been made available on the World Wide Web by the Geography Department of the University of Alabama and other institutions, which should increase their use.[13]

These maps are of particular interest because of their extraordinary detail and accuracy ( 10.5).For many areas, they provide us with the earliest reliable picture of the landscape. They show individual structures (but include the names of very few homeowners). Important buildings, such as churches, factories, and mills are usually identified. Roads are shown in detail, with some effort being made to differentiate between different types of roads (such as paths, county roads, and turnpikes). Hills are depicted, usually by a system of shaded relief. An unusual feature of many of these sheets is that they show different types of land cover. Fields, marshes, and orchards are identified by conventional symbols. On some sheets, efforts were made to differentiate between grasslands, brush, woodlands, and coniferous forests. For example, the Pine Barrens on Long Island are represented by drawings of tiny pine trees.

10.5. U.S. Coast Survey, manuscript survey sheet T-25 [area around Cold Spring Harbor, Long Island]. Stony Brook University Library.

As might be gathered from the preceding description, these maps can be difficult to interpret. They generally do not present many problems for those familiar with the conventions used on eighteenth and early nineteenth century maps, or who have enough local knowledge to decipher unfamiliar signs. But for students and others without sufficient background, they can be exceedingly difficult to read. In spite of Hassler’s fanaticism about precision, he seems to have provided little guidance to his assistants about how to go about sketching the details of their work. The amount and type of information shown varies considerably from map to map—especially between those made by different surveyors. There are also variations in the symbols used, even for such common matters as the depiction of buildings and marshes. For example, on most maps buildings are shown as dark squares or rectangles. On some sheets, however, outbuildings, such as barns, are shown as hollow rectangles.

No field notes were taken by Hassler’s surveyors. Hassler thought they were unnecessary because of the detail and accuracy of his surveys, but their lack is felt by researchers looking for information to explain or supplement his maps.

Hassler appears to have issued his first written instructions for surveyors in 1841, and to have prepared the first legend of symbols for the Coast Survey at about the same time. The legend was published in 1844, shortly after his death.[14] By this time, many of these manuscript maps had been completed, and even then this legend does not deal with such subjects as types of vegetation, although it goes into great detail on such matters as how to depict different types of bridges. Only later in the nineteenth century did the Coast Survey succeed in establishing a more comprehensive system of standardized symbols.

Very few maps were actually published by the Coast Survey during Hassler’s lifetime, and they are of small harbors, such as New Haven. However, within a few years of his death, several maps were published based on his surveys and covering parts of New York. The first of these was his famous map of New York Harbor (1844), which was actually in press at the time of Hassler’s death.[15] This huge map on six sheets was drawn at a scale of 1:31,000; a single-sheet version was published in 1845 at a scale of 1:80,000.[16]

The map of New York Harbor is widely regarded as Hassler’s masterpiece. It is available online, and it is the best expression of how he intended his maps to appear. In addition to New York Harbor, it includes parts of southern Manhattan, Staten Island, New Jersey, and western Long Island. At a scale of 1:31,000, it is detailed enough to include much (but not all) of the information on the manuscript sheets at scales of 1:10,000 and 1:20,000 (see 10.6). This is especially evident in rural areas, which at that time still included most of the modern boroughs of Brooklyn, Queens, and Staten Island. Here individual buildings are shown, along with their surrounding lots. Fields are also depicted, as well as marshes, woodlands, and hills. Urban areas, such as Manhattan, show streets (without names), along with a few other features, especially docks and parks.

10.6. Detail from Hassler’s New York Harbor chart (1845). Library of Congress, Geography and Map Division.

As a navigational chart of New York Harbor, Hassler’s masterpiece clearly surpasses all of its predecessors. Aside from its outstanding geodetic precision, it is much richer than any previous chart of the harbor in the number of its soundings, and in its depiction of channels, shoals, and other standard navigational features. The favorable reception that this chart received from merchants and navigators was widely seen as a vindication of Hassler’s painstaking methods. Hassler’s survey was particularly praised for its discovery of “Gedney’s Channel,” a deeper and straighter entrance to New York Harbor in the vicinity of Sandy Hook.[17]

In the course of the 1840s and 1850s, the Coast Survey published charts showing all of the coastlines and waters around Long Island at a scale of 1:80,000.[18] Several charts of individual harbors and other limited areas were published at larger scales.[19] Even at 1:80,000, these charts were on a large enough scale to include much of the inland detail found on the manuscript maps. However, this detailed topography is only provided for areas within a few miles of the coast. Areas in the center of Long Island were left blank, which means that the extensive information recorded in the manuscript surveys of these areas was never published. This marks the beginning of a trend on Coast Survey charts to exclude inland detail, a trend which accelerated through the nineteenth century—especially after inland mapping was taken over by the USGS. Modern nautical charts show only a few features away from the shore, and they are mostly landmarks useful for navigation.

Coast Survey Mapping in New York after Hassler

Hassler’s death in 1843 marked an important turning point in the history of the Coast Survey. To the very end, Hassler faced constant battles with Congress to justify the existence of the Coast Survey, and to defend it against charges of excessive expense and snail-like progress. His successor, Alexander Dallas Bache (1806-1867) managed to put the Coast Survey on a firmer footing.[20]

A great-grandson of Benjamin Franklin, Bache was trained as a military engineer at West Point. After 1828, he was appointed professor of natural philosophy at the University of Pennsylvania, and quickly became one of the recognized leaders of American science. Bache not only had the technical skills to lead the Coast Survey, but he also had extensive personal connections, as well as political and administrative skills that Hassler lacked.

Under Bache, the Coast Survey quickly extended its operations to the southern and western shores of the expanding nation. By focusing on geodesy and coastal charting at the expense of mapping inland areas, and by various technical improvements, he was able to increase dramatically the publication of maps, which in turn helped lead to higher appropriations for the Coast Survey. By the late 1840s, the value of Coast Survey charts for maritime commerce was widely recognized. During the Civil War, the Coast Survey under Bache made important contributions to the Union war effort.[21]

As far as New York is concerned, Bache’s main contribution was the publication of maps based on surveys previously carried out under Hassler. The most significant new work done under Bache was a detailed resurvey of New York Harbor, which was conducted in the 1850s. He also extended the production of both manuscript and printed maps of the Hudson River Valley as far north as Albany.[22] The modesty of these contributions is explained by his focus on extending the activities of the survey to the south and the west.

The subsequent history of the Coast Survey in New York can be quickly summarized. In the 1870s and 1880s, the agency (renamed the Coast and Geodetic Survey in 1878) extended its activities to the upper Hudson River and Lake Champlain. Along with the production of charts, this involved a considerable extension of its triangulation network. This network by no means covered all of New York, but (as we shall see), it was extended by other state and federal agencies at the end of the nineteenth century and at the beginning of the twentieth. In the 1870s and 1880s, the Coast Survey (after 1878 the Coast and Geodetic Survey) also conducted a new survey of Long Island, which led to a second set of detailed manuscript maps (showing coastal areas only), and a variety of printed charts of the waters around the island. Almost all of these historical published charts are available on the World Wide Web.[23]

There is a direct line of succession from the Coast Survey, through the Coast and Geodetic Survey, to the National Oceanic and Atmospheric Administration (created in 1970). After the creation of the Coast and Geodetic Survey in 1878, the mapping of areas away from the coast was assigned to the United States Geological Survey (USGS), and the Coast and Geodetic Survey was restricted to mapping the coast and maintaining the geodetic framework of the United States (mainly through triangulation until the middle of the twentieth century).[24]

It is generally recognized that the methods introduced by Hassler form the foundation of the later activities of both the USGS and the Coast and Geodetic Survey. Thus, Hassler can truly be said to have laid the foundations of “scientific mapping,” as it was understood in the United States until the middle of the twentieth century.

It may legitimately be asked: what is the significance of this achievement? In my view, it is misleading to simply celebrate Hassler’s accomplishments, and to dismiss his opponents as wrong-headed and unprogressive. Maps should be evaluated in terms of the needs they served and placed in the context of the times in which they were created. This historical approach calls for asking questions like: Why were they created? Who used them? How successful were they in serving their purposes? This approach is implicitly utilitarian, since it assumes that people do not go to the considerable expense in time and money of creating maps without practical reasons for doing so.

In the case of the Coast Survey maps, their creators and advocates were quite explicit about why they thought they should be made. The words “commerce” and “defense” sum up the bulk of their arguments. The supporters of the Coast Survey also used phrases like “the advancement of science,” and suggested that in addition to advancing such obscure sciences as geodesy, the Coast Survey led to useful discoveries in other areas, such as meteorology and oceanography. This argument was frequently tied into patriotic calls for raising national prestige—i.e. calling for Americans to prove that they are at least equal to Europeans in their scientific accomplishments.

On the whole, the advocates of the Coast Survey made their case. Their charts were successful in making coastal navigation safer and more economical, and they were able to gather numerous testimonials in support of their value in that respect. The case for “defense” is more equivocal than that for “commerce.” True, the coastal charts were useful to the North in the Civil War, but the southern states might have regarded them in a different light. The Coast Survey charts outside of the South were never tested for defense purposes by a foreign invasion. Had the United States gone to war with Great Britain in the last half of the nineteenth century, it is not hard to imagine that they might have been more useful to the invaders than to the Americans, who would have had the advantage of being relatively familiar with their own territory. (This is one reason why even today some nations keep their detailed maps secret.)

In terms of advancing science and national prestige, the Coast Survey seems to have met with considerable success, although this is harder to measure. Judging from reviews and remarks in foreign scientific journals, American science was regarded with greater respect and appreciation thanks to the activities of people like Hassler and Bache. Certainly, the closely associated activities of Coast Survey and military map makers succeeded in creating a cadre of skilled cartographers in the United States, and in raising the level of scientific activity in this country generally.

Where Hassler’s objectives are most open to question is in the matter of land-based topographic mapping. Although this was not the primary objective of the Coast Survey, it was clearly important to Hassler. The effort he devoted to this activity slowed down his work, and much of it was abandoned after his death. Here it can be argued that Hassler was truly “ahead of his time” in that there was not a clear-cut need for detailed topographic mapping in early nineteenth century America. Hassler’s critics— who included surveyors like Andrew Ellicott, Isaac Roberdeau, and Simeon De Witt, as well as ignorant congressmen—had a point. Maps like those produced by De Witt and David Burr seem to have served their purposes well. They were sufficiently exact to enable people to find towns and major landholdings, and to get from one place to another by road or river. As long as boundaries met a reasonable standard of exactitude (as defined by the surveyor general’s office) they were good enough. Problems could be corrected by additional surveys, or by negotiation, or in court. The press was not full of complaints about problems caused by inadequate mapping in New York. Why, then, spend large amounts of time and money on expensive surveys?

This question was to hang over the mapping of New York for much of the nineteenth century. We will see how it was answered over time, and how eventually precise and detailed topographic mapping came to be seen as desirable and even necessary.

Special Purpose Maps: Geology, Soils, and Public Health

Scientific mapping in nineteenth-century New York involved more than producing geodetically accurate maps using precision instruments and advanced methods of surveying. The new preoccupation with precise measurement in cartography, reflected in the work of the Coast Survey, is related to a broader phenomenon known as “Humboldtian science.” As a concept, Humboldtian science (named after its leading practitioner Alexander von Humboldt) is difficult to define, but it is important for understanding the development of science in the nineteenth-century. Humboldtian Science was not the result of some kind of scientific revolution, paradigm shift, or epistemic change. Rather, it was more a reconfiguration and change of emphasis in trends that were mostly in place in the eighteenth century. Precise mapping based on careful observations and record keeping is only one aspect of Humboldtian science. Equally important is the use of statistics to study the geographical relationships between a wide range of natural and human phenomena. We can see this linkage with geography in a number of fields that were prominent in the first half of the nineteenth century, including geodesy, astronomy, geology, meteorology, the study of tides, and the study of the distribution of plants and animals.[25]

Humboldtian science is also connected with the development of “thematic maps.” There is no completely satisfactory definition of what is meant by thematic mapping, but it is generally accepted that it involves the portrayal of geographically distributed information that is not readily visible on the surface of the earth (although conventional maps also include certain types of “invisible” information, including borders and boundaries, military movements, and contour lines). Typically, thematic maps focus on the geographical distribution of one particular subject. For purposes of this book, I am considering thematic maps to include geological maps, soil maps, and meteorological maps, as well as maps showing the geographical distribution of such things as plants, animals, religions, and languages. Statistical maps—which show such things as the numerical distribution of diseases, or of census or economic data—are the most undisputed form of thematic mapping.[26]

The earliest examples of thematic maps have been traced back at least as far as the Renaissance. Edmund Halley’s world maps showing wind directions and compass deviation, produced around 1700, have often been cited as pioneering examples. But thematic maps did not really start to flourish until the nineteenth century. One reason for their relatively late development is that most thematic maps are closely linked to techniques for the collection and classification of information that were largely developed in the eighteenth and nineteenth centuries. Also, the flourishing of thematic mapping reflected the increasing awareness after 1800, characteristic of Humboldtian science, of the interconnectedness between geography and other disciplines, such as botany and geology. As geographer Arthur Robinson has pointed out, the use of maps that show such things as geological or statistical information constitutes a major conceptual revolution in map making.[27]

Several pioneering efforts in thematic mapping took place in New York State.

Disease Mapping

The first thematic map published in New York is also something of an historical anomaly. This is Valentine Seaman’s pioneering map of yellow fever deaths on what is now the Lower East Side of Manhattan.[28] Seaman, a surgeon at the New York Hospital, believed that yellow fever was caused by “putrid effluvia” associated with the Roosevelt Street Drain on the lower East Side of Manhattan, and he made a map showing the frequency of cases of the disease in its vicinity. Seaman’s theory was wrong, since we now know that Yellow Fever is a mosquito-born disease, but his map correctly reflected the association between the disease and standing water.

Remarkably, Seaman’s map is thought to be the world’s first “spot map” showing the geographical distribution of specific incidences of a disease.[29] It preceded by more than fifty years John Snow’s famous maps of the epidemiology of cholera in London, which stimulated the widespread publication of disease maps throughout the world. Other simple maps showing disease outbreaks in lower Manhattan were published in 1819 and 1821.[30] Later and more elaborate developments in public health mapping of New York will be taken up in Chapter 12.

Geological and Soil Maps

Most of the early efforts at thematic mapping in New York took the form of geological and soil maps.[31] Soil mapping and geological mapping originated at about the same time, and were often practiced by the same individuals. Contrary to modern theory, it was generally believed in the early nineteenth century that soil types were mostly determined by underlying rock formations, and early soil classifications were based on the types of rock from which the soils were thought to have been derived. Thus, there was little difference between soil maps and surface geological maps.

Soil and geological maps started to appear in late eighteenth-century Europe. They could not have come into being were it not for the existence of systematic ways of classifying geological formations and soils, which being were developed at that time. The earliest geological and soil maps appear to have been made in France and Germany in the last half of the eighteenth century.[32] Much better known in the English-speaking world is William Smith’s pioneering geological map of England and Wales, which was first published in 1815.[33] But by that time the first geological maps of the United States (including New York) had already appeared. The earliest was published in France by the Comte de Volney in 1803; the first by an American was published by William Maclure in 1809.[34]

New York’s most important pioneer in mapping geology and soils was Amos Eaton (1776-1842). Eaton was born in Columbia County, New York, and educated at Williams College. After graduation, he studied law in New York City, and pursued a career as an attorney, surveyor, and land agent in Catskill, New York. The turning point in his career came in 1811, when he was convicted (probably wrongly) of forgery in a land dispute, and spent five years in prison. After his release, he decided to pursue a career as a scientist, and studied biology and geology at Yale. In his later years, he made important contributions to botany and geology, played an important part in science education, and helped found Rensselaer Polytechnic Institute.[35]

Eaton’s involvement in geologic mapping began in 1817, when he returned to New York State and was invited by De Witt Clinton to give a series of lectures to the state legislature on the geology of the Erie Canal area. In New York, as in Great Britain, there was a close connection between canal construction and early geological mapping: knowledge of underlying rock formations was necessary to determine the feasibility of building canals, and the investigations associated with canal construction were sources of data for geological maps. Shortly after delivering these lectures, Eaton was hired to conduct geological and soil surveys of Albany and Rensselaer counties.[36] Much of Eaton’s work was financed by Stephan Van Rensselaer, who served as a kind of patron for him. Eaton went on to conduct a geological survey of the route of the Erie Canal, which included a geological cross-section of the entire corridor from the Atlantic Ocean to Lake Erie.[37]

Eaton’s actual maps are of interest mainly to historians of science. His classification of rocks was based on the Wernerian or “Neptunist” system, which posited that most rocks were formed by the crystalization of minerals in ancient oceans. Eaton’s pioneering work and its underlying “Neptunist” theories quickly became obsolete, and no one would today consult his maps for geological information, although they were an impressive achievement for his time, and formed a foundation for later investigations. His early maps took the form of geological profiles (or cross sections), rather than geological maps of horizontally extended areas. As was noted in the previous chapter, his geological profile of the Erie Canal was also published in 1823 as part of D.H. Vance’s map of Western New York; Dey’s 1825 edition of Vance’s map includes a later version of Eaton’s profile, which extends as far as the Atlantic Ocean ( 10.7).[38] Only in 1830 did he publish a map of showing the surface geology of the entire state.[39]

10.7. Detail of Amos Eaton’s Geological Profile of Erie Canal (1825). Courtesy David Rumsey Collection.

The focus of much of the later thematic mapping during this period was the New York Natural History Survey (1836-1894?).[40] This survey was the most ambitious scientific project undertaken by the state in the nineteenth century. Although not the first statewide natural history survey, the New York survey had the reputation of being particularly thorough and well done, and its impact on the development of natural science in nineteenth-century America was appreciable.

The survey was created for a variety of reasons: the advancement of mining and agriculture vied with the more abstract and less utilitarian “advancement of science.” The survey included sections on botany, zoology, paleontology, and mineralogy, but as far as cartography is concerned, the sections dealing with geology are of primary importance. In addition to several geological maps, these four volumes include many geological cross-sections, and a number of beautiful panoramic views, which also shed light on New York’s landscape in the middle of the nineteenth century. The most important cartographic contributions were made by four individuals: Ebenezer Emmons, W.W. Mather, Lardner Vanuxem, and James Hall. They were responsible for the geological mapping of the state, which was divided into four parts, all of which were published in 1842-43.[41] Of the four geologists, Emmons, Mather, and Hall were primarily concerned with mapping. Vanuxem concentrated almost entirely on stratigraphy and paleontology.

Ebenezer Emmons (1799-1863) was born in Western Massachusetts, and educated as a physician at Williams College. Later he became interested in geology, which he studied under Amos Eaton at Rensselaer Polytechnic Institute, receiving a degree in 1826. As early as 1824, he had assisted in the preparation of a geological map of Berkshire County (Massachusetts). Later, he worked as zoologist on the Massachusetts Survey from 1830-1833. With the creation of the New York Natural History Survey in 1836, he was named geologist of the Second Geological District, which included most of the Adirondacks. As a geologist, he made major contributions to the “New York system” of Paleozoic stratigraphy, which has had a major influence on the development of American geology.

While working with the survey, Emmons conducted extensive explorations in the Adirondacks. He is credited with naming both the Adirondack and the Taconic Mountains. In the course of his explorations, he also made the first known ascent of Mt. Marcy (1837), which he named for New York State Governor William Learned Marcy. These explorations also led him to become acutely aware of the deficiencies of existing maps of the Adirondack region, where he noted missing or misplaced mountains, rivers, and lakes. Emmons’ annual reports and his final report include numerous views and geological profiles, along with some maps (including maps of Clinton and Jefferson counties, which appeared in his final report). His corrections to the topography of the region are reflected in a map that he published of his district in 1842, and in two later geological maps of the state as a whole, which will be discussed below. His mapping of the Adirondack region was widely copied, and he thus made a major contribution to the understanding of the geography of this region.[42]

For those particularly interested in the exploration and mapping of the Adirondacks, mention should also be made of a detailed report submitted by Farrand N. Benedict to the Legislature in 1846 on the route of a proposed railroad through the central Adirondacks from Lake Champlain to Oneida County.[43] Benedict had earlier worked with Emmons, and carried out surveys and measurements of altitudes for him in the Adirondacks.

Emmons’ colleague, W.W. [William Williams] Mather (1804-59), was a descendent of Cotton Mather, and, like many early nineteenth-century American cartographers, a West Point graduate. (Prior to the establishment of Rensselaer Polytechnic Institute, West Point was the only institution in the country that taught engineering and surveying.) Mather also had served as “topographical engineer” on the geological survey of the Wisconsin territory, which was headed by the controversial English geologist on George W. Featherstonhaugh.[44]

Mather served in the New York State Survey as Geologist of the First District, which included Long Island, the Catskill region, and the Hudson Valley. Although not as actively involved in exploration as Emmons, Mather faced similar problems in mapping his district. He, too, complained about the inadequacy of existing maps as a base for depicting the geology of his region. Mather’s major contribution to the mapping of New York was his Geological Map of Long & Staten Islands with the Environs of New York, which was published as part of the survey in 1842.[45] As a base for this map, he used a map of Long Island by J. Calvin Smith (which in turn was based partially on Coast Survey maps).[46] For the upper Hudson Valley, Mather compiled his own topographical base maps from a variety of sources.[47] He did not publish a separate geological map for the Hudson Valley region in his report, although it included numerous geological cross sections and a few maps of small areas.

James Hall (1811-1898) was just beginning his distinguished career as a geologist and paleontologist. Hall was a student of Eaton and Emmons, and he began his work on the survey as an assistant to Emmons. He was later put in charge of the fourth district, which covered western New York, where he made important contributions to unraveling the stratigraphy of that part of the state. In his later career, Hall became New York State paleontologist, and made numerous important contributions to both geology and paleontology, including a revised geological map of the state published in 1894.[48]

Hall’s most important contribution to the survey was A Geological Map of the Middle and Western States , which appeared in the fourth volume of the report (1843).[49] According to Leighton, “this map has had a powerful influence on the geology of the eastern United States. [It] indicates the phenomenal advance made in stratigraphy since the publication of Eaton’s map of the State 12 years before, and Hall’s map appears with divisions, a number of which have remained almost as set down, to the present day.”[50] In addition, the illustrations in Hall’s volume include a bird’s-eye view of Niagara Falls and numerous geological cross-sections. Of particular interest, Hall also included a carefully done “Trigonometrical Map of Niagara Falls,” which was based on careful surveys he conducted with E.R. Blackwell, and which later was used in studies of the recession of the falls.[51]

The final report of the survey included a geological map of the entire state, which synthesized the material compiled by the four geologists.[52] There was a good deal of wrangling over the contents of this map, which was caused largely by a disagreement between Emmons and his colleagues over the place of the Taconic formations in the New York system.

All of the geologists agreed that their work was made more difficult by the lack of satisfactory general purpose maps to use as base maps for their work. At the beginning of the Natural History Survey, it was thought that the geologists could base their maps on the county maps in the Burr atlas.[53] But in the course of their work the geologists found them so inaccurate that they could not rely on them, and in some cases compiled their own maps, as we have seen in the case of Mather. Accordingly, for the final geological map a special base map was engraved for the Survey, which was then colored in by hand following the directions of the geologists.[54] This base map was engraved by the firm of Sherman and Smith, which included J. Calvin Smith, whose map of lower New York State had previously been used by Mather. Although it did not show relief, this map provided a remarkably good depiction of the lakes and streams of the Adirondacks. Overall, it was still not entirely satisfactory to the geologists, and the need for better topographic maps to serve as base maps for geologic mapping made geologists like James Hall strong advocates for a comprehensive state mapping program in the following decades.

The 1842 geological map resembles modern geological maps of New York much more closely than Eaton’s earlier production, and it is an important landmark in the mapping of the state. Emmons modified the map slightly in 1844 to reflect his ideas about the Taconic system, but otherwise it remained the definitive map of New York’s geology until the end of the nineteenth century.

It is significant that no maps showing the distribution of animals or plants were produced by the survey. This is in spite of the fact that the scientists involved with zoology and botany paid considerable attention to the geographical distribution of species, and that vegetation and animal distribution maps were already being produced in Europe. Apparently the scientists working on the New York State Survey were either unaware of the European species distribution maps, or it did not occur to them that this type of map might be useful in their own work. Maps of this kind were still relatively new, and it appears that it required a kind of conceptual shift before American scientists could recognize their value.

After the conclusion of the geological portion of the natural history survey in 1842, Emmons was requested by State Legislature to conduct an agricultural survey of New York. The first volume of this survey, published in 1846, includes several panoramic views and two maps. One of the maps was a revised version of the 1842 geological map of New York, which Emmons changed to reflect his views on the place of the Taconic System in the state’s geology.[55] Also in this volume was an Agricultural Map of the State of New York.[56] This is an early example of a soil map. Emmons divided New York into six districts, which he thought were characterized by broadly different soil types. Emmons characterized soils by the kinds of rocks from which he thought they were derived, and conducted chemical tests to determine soil compositions. He realized that the soils of New York were much more complex than the six basic types that he mapped, but he was not in the position to conduct the detailed surveying necessary to produce a more elaborate map.

Mapping the Croton Aqueduct

The construction of the Croton Aqueduct between 1837 and 1842 was, after the Erie Canal, the state’s largest engineering project prior to the Civil War. It assured New York City of an adequate supply of drinkable water, and it was vital for fire protection, thus making it essential for the city’s future growth and well being. It brought water from the Croton River on the border between Westchester and Putnam counties to Manhattan through a forty-five mile aqueduct, which required the construction of an extensive system of reservoirs, pipes, tunnels, and bridges. The completion of this project, like that of the Erie Canal, was accompanied by great public festivities, and elicited the production of a variety of maps, ranging from the technical to the celebratory.[57] These can be described as “hydrographic maps,” which are a form of thematic maps closely related to geologic maps.

An overview of the Croton Aqueduct system can be obtained from Nathaniel Currier’s Hydrographic Map of the Counties of New-York, Westchester and Putnam: and Also Showing the Line of the Croton Aqueduct.[58] More specialized is an intriguing map of lower Manhattan, which shows in detail the network of pipes and valves for distributing water from the aqueduct. It was apparently prepared for the Croton Aqueduct Department and lithographed by George Endicott sometime between 1842 and 1845.[59] A number of other specialized maps were created in connection with this project. Most involved land that was being condemned and acquired for reservoirs associated with the aqueduct, but there were also several cross-sections, which resemble the geological profiles prepared in connection with the Erie Canal.[60] Later in the nineteenth century, New York’s water system was expanded to include most of the present network of aqueducts and reservoirs in the Catskill region.

Other Thematic Maps

Very few thematic maps dealing with subjects other than soil, water, or geology were published in New York or elsewhere in the United States prior to the Civil War. This lack is particularly notable in the case of “statistical maps,” which show the geographical distribution of data that can also be summarized in tabular form. By the 1840s, statistical maps had become fairly common in Europe, but they were slow to appear in this country.[61] As earlier noted, it required a considerable conceptual shift to conceive of mapping many things that do not actually appear on the surface of the earth, and arguably this applies to statistical abstractions more than to rocks and soils. But this in itself does not seem sufficient to explain the slow appearance of statistical maps in the United States, since Americans quickly recognized the merits of Berghouse and Johnson’s groundbreaking Physical Atlas (1848), which contains a number of demographic and other statistical maps.

This type of thematic mapping depends on the collection of statistical information, which in the early nineteenth century was less widely available in the United States than in Europe. But some statistics were available, particularly population statistics from the census, so lack of data also does not by itself explain the American slowness to create statistical maps.Remarkably, the first maps based on U.S. census data were published in 1855 in Germany by August Petermann using information from the 1850 census. It should also be noted that the publication of elaborate thematic maps requires sophisticated engraving and lithography, and these arts were also more advanced in Europe than in the United States. Most likely, some combination of these reasons explains the slow development of thematic mapping in the United States. Interestingly enough, a number of maps and atlases published in the United States in the first half of the nineteenth century contained statistics in tabular formshowing an increasing interest in this type of thing, and the beginnings of an association between maps and statistical information.[62]

The few thematic maps that appeared in the United States during this period were published in books or articles, rather than as separate publications, which makes it difficult to track them down, since such materials do not usually appear in library catalogs. The only thematic maps of New York that I have been able to locate (other than those discussed above) are insets in general-purpose maps. It has already been noted that Amos Eaton’s geological cross-section of the Erie Canal was reprinted on Vance’s map of western New York. Particularly interesting is the appearance of two thematic maps as insets on J.H. French’s important 1859 map of New York State, which will be discussed in the following chapter.[63] Both of these inset maps were fairly sophisticated productions.

The first of the insets is an unusual hybrid—a geological and land patent map of New York State ( 10.8). There is no obvious reason why these two unrelated subjects should appear on the same map, other than that French probably wanted to cram as much information as he could into a small space. This map was probably derived from a larger map with the same title prepared by or for Robert Pearsall Smith, who was closely associated with J.H. French in publishing maps of New York.[64] This separate map appears never to have been published, but, interestingly, Smith himself announced in 1848 that he was planning to produce a Physical Atlas with thematic maps by “Berghaus & Johnston.”[65] In any case, the appearance of an up-to-date geological map as an inset on a map intended for the general public is noteworthy, since it shows that there must have been fairly widespread interest in this kind of information. The geological portion of this map was based on the work published by the New York State Survey in 1842.

10.8. Geological and Land Patent Map. Inset from J.H. French, State of New York (1860). Courtesy of the David Rumsey Collection.

The other inset on the French map of New York appears to be the first published meteorological map of the state. It bears the title: “Meteorological Map Showing Average Mean Temperature, Depth of Rain, and Direction of Winds at the Several Meteorological Stations Established by the Regents of the University.” The study of meteorology was another characteristic form of “Humboldtian Science,” and New York played a pioneering role in establishing this discipline in the United States. The map was drafted by Lorin Blodget, an important in early American meteorology.[66] It would obviously have been of practical interest to farmers, among others. It used the technique of isothermal lines to show regional differences in mean temperatures. Isothermal lines had been devised in the early nineteenth century by Alexander von Humboldt, and had started to appear on German and British maps in the 1840s.

Although Blodget’s work cannot be described as pioneering in a global context, it is remarkable that it should have been published in New York in 1859. Both of the inset thematic maps on the French map seem to indicate that the conceptual adjustments necessary to read and understand such maps did not pose much a problem to New Yorkers by the time of the Civil War. The ground was already prepared for the reception of large numbers of varied thematic maps later in the nineteenth century.