Slide Sets

After receiving a patent dated March 25, 1584, from Queen Elizabeth to settle all lands in the mid-Atlantic region of North America not possessed by a Christian prince, Walter Raleigh financed a successful reconnaissance voyage to the Outer Banks of what is now North Carolina on April 27, 1584. Raleigh's next move was to organize a fleet of colonists under the governorship of Ralph Lane which left England on April 9, 1585, to settle a colony in what was then called Virginia on Roanoke Island near the site of present day Manteo, North Carolina. One of the goals of this colony was to survey and map Raleigh's new domain. To carry out this survey, Raleigh sent one of his closest advisors, Thomas Hariot (sometimes spelled Harriot), who was one of Renaissance England's greatest mathematicians and astronomers, and John White, a relatively unknown artist. This team combined their talents to create the first maps of America based on a detailed survey.

This slide set pictures the most important instruments and techniques that Hariot and White probably used to conduct their survey. (It also reproduces the Hariot-White-de Bry map of the Outer Banks that their survey produced.) Any account of their survey techniques must be conjectural because no instructions have survived that the two probably received from Raleigh and his associates. However, instructions, written by an unknown hand, do exist for another expedition surveyor, Thomas Bavin, who was to have sailed on a voyage to America in 1582 or 1583 that never materialized. These instructions indicate exactly what Bavin was to accomplish and how he was to conduct his survey.

It is impossible to say with any accuracy what experience Hariot and White had as surveyors before 1585. Hariot was undoubtedly familiar with the instruments and mathematics of Renaissance surveying. Raleigh hired him in about 1579 as his personal tutor in mathematics. Hariot later established and taught in a school to train Raleigh's sea captains in the developing art of open sea navigation, a discipline that used many of the instruments also used by English surveyors of the time. His duties included collecting state-of-the-art instruments and teaching the captains how to use them and the basic mathematics needed for transatlantic navigation. To accomplish this, he wrote the Arcticon, a lost navigational manual. In preparation for the 1585 voyage, he probably collected and studied the newest materials on surveying.

White probably had experience in surveying, but his must have been more practical than Hariot's. His drawings of the temporary encampments that Lane constructed in Puerto Rico and Salina during the voyage to the Outer Banks suggest that he had a background in estate and perhaps military surveying. In England at the time, artists often helped draw and color elaborate estate and house plans for wealthy builders. These illustrations were often decorated and colored to emphasize special features of the manor house and its estate and then hung as wall hangings.

One of the first operations Hariot and White probably performed in Virginia was to determine their location on the earth's surface. To accomplish this, they needed to establish their latitude (the distance north of the equator) and their longitude (the distance west of a prime meridian, probably near London).

To determine their latitude, they might well have used one of the oldest and most widely used Renaissance instruments of survey and navigation, the cross staff, which mariners and surveyors used to measure vertical angles. Made of wood, the staff consisted of two major parts, a long, graduated staff and a transom or crossbar that slid up and down it. The staff had scales marked on each of its four sides, and these scales corresponded to up to four transoms, each a different length. Renaissance surveyors and navigators used the cross staff to measure the angle of the sun or another star above the horizon, the height of the celestial body determining which length transom to use. As this slide shows the cross staff could also be used to determine the height of a building, mountain, or other vertical object.

To use the cross staff, surveyors and navigators began by estimating the length of the crossbar needed by the height of a celestial body, the sun, for instance. After sliding the bar onto the staff, they would point the staff in the direction of the sun, placing the sighting end of the staff against their eye socket or cheek. They then adjusted the crossbar by sliding it up and down the staff until one end of the bar was on the horizon and the other was on the sun. After adjusting the transom properly so that it fell across the proper degrees on the staff, they would then read off these degrees to determine the angle of the sun above the horizon. To determine latitude required them to take an additional step in their calculations. They had to sight the sun at its meridian, its highest point in the sky at exactly noon. Then they used figures from Ephemerides charts (which Bavin was to have taken with him) that gave figures of the sun's ecliptic determined by the date to calculate their latitude. The charts were necessary because they contained information on the irregularity of the calendar year, the oblique track of the sun across the sky, and celestial changes caused by the precession of the equinoxes (Brown 198), all of which needed to be calculated in to determine exact latitude.

While methods for determining latitude had been worked out by the 1580s, those for determining longitude had not yet been. While calculating latitude required surveyors and navigators to establish their north-south position in relation to the equator, establishing longitude required them to calculate their distance east or west of an arbitrary meridian, which for Hariot and White probably would have been near London. Fixing the longitude of the Outer Banks would require White and Hariot to determine how many degrees they were west of London, and they could accomplish this only by knowing what time it was in London when the sun was at high noon in Virginia. Once they had these two times, they could easily calculate their longitude because each four minutes of time equaled one degree of longitude. That Hariot and White had timepieces with them suggests they were to attempt a calculation of longitude, but their primitive wind-up watches could not keep London time accurately enough for the task.

In addition to establishing the position of the Outer Banks on the earth's surface, Hariot and White had to orient their map to the four directions. Two instruments surveyors and navigators used to achieve this orientation were the magnetic compass and the universal dial, often called the universal ring dial, both of which Bavin's instructions mention. These two were sometimes combined into a single instrument, as this slide shows. Both instruments oriented the user to the north.

By the late 15th century the compass had become a standard instrument in English surveying. As early as 1523 Master Fitzherbert recommended in the first book on English surveying that the compass be used to establish the alignments of parcels of land in estates. In fact, basic surveys could be conducted using the compass alone, and these are now known as compass traverse surveys. Renaissance surveyors would first determine north, set their compass, and then walk or sail along the line (such as a coast) or around the area they wished to survey, using the compass to take bearing at every turn made. This method would give a rough outline of a coast or an area of land, and Hariot and White might well have used it to construct their sketch map of Virginia. Traversing, however, allowed errors to creep into the map. Because surveyors had to keep track of distance by pacing or sailing, the various legs of the traverse would by necessity be approximations. Also, because the compass was subject to outside influences, such as iron deposits, for instance, the bearings and the angles based on them were not always accurate. Hariot and White probably used the more sophisticated method of triangulation with a plain table or a theodolite to conduct at least part of the surveys of their finished maps, which are highly accurate.

One problem with the compass was that it showed magnetic, not true, north. The difference between these two came to be called the declination or variation of the compass, a phenomenon that Columbus discovered on his first transatlantic voyage. To determine true north, Renaissance instrument makers devised the universal ring dial, an instrument that could either be used alone or, as this slide shows, attached to a land compass. Introduced to England in 1542 by Jean Rotz, the French mapmaker, this was a valuable instrument which, in addition to identifying true north, could also tell local time, accomplishing both by measuring the altitude and direction of the sun or a bright star. To use it the surveyor would adjust the dial to the proper latitude, which he could find using his cross staff and tables. Next, he would set the pinhole slide to the proper date. Then, at noon, he would turn the dial until a ray of light, shining through the pin hole, fell on the hour circle, which could only occur when the dial was aligned exactly to true north. When mounted over a compass, as Bavin's apparently was, the surveyor could measure the compass variation directly. That Bavin was to use a dial is clear from his instructions: "by your universall dyal you may alweis finde the variacion of the Compasse att noonetyde by observing how fare your Compasse dothe differ from your just meridian" (242). The instructions go on to emphasize the care with which Bavin was to make and then check his directions. He was to mark both magnetic and true north on his draft map and then check true north again by taking a reading of the pole star from the same location.

Because of the high degree of accuracy of their finished maps, Hariot and White probably used methods other than the compass traverse method to survey the Outer Banks. By the late 16th century, triangulation had become well established in England. This slide pictures the method of triangulation that Arthur Hopton recommended in Speculum Topographicum, or The Topographical Glasse (1611) for surveying relatively large areas, in this case the county of Sallop. As the term triangulation suggests, the surveyor made observations in the shape of triangles to determine the area of the piece of land and either recorded these angles in a notebook and used them to sketch out a map later or sketched these triangles in the field directly on a sheet of paper attached to a plain table (see slide 4).

Triangulation was based on the geometry of the triangle, and it remains today a standard method of mapmaking. To use it the Renaissance surveyor established two stations of observation. In Hopton's example, these two points were "Cordocke Hill," labeled F, and "Wrenkin Hill," labeled G. These two points were elevated so that the surveyor could see all the surrounding territory. Hopton then recommended that the surveyor set up his angle-measuring instrument (such as a plain table or a theodolite) on point F and sight the prominent features of the landscape, such as Hopton Castle, Montgomery, and the other places listed on his chart on pages 38 and 39. The surveyor would then record the angles between his sight lines and his base line (F to G), moving systematically around the circle. He then would transport his instrument in the exact direction it was at F and sight the same prominent features. By taking two sightings of the same objects, the surveyor created a network of triangles. Once the surveyor determined the length of any one line in the network (Hopton mentioned that nine miles separated Cordocke Hill and Wrenkin Hill), he could easily determine using a two-legged compass the proportional distance of all lines in the skeleton map he has sketched. To create the map the cartographer would flesh out his skeleton to create a finished product. In Hariot and White's collaboration, Hariot probably, perhaps with White's assistance, conducted most of the actual survey and carried out the necessary mathematical calculations; the artist probably helped in the field and then drew the finished maps from the mathematician's calculations.

One of the primary instruments of triangulation that Bavin had was the plain table, which had come into use in England by the beginning of Elizabeth's reign. Hariot and White undoubtedly had such a table, and if mathematical calculations were beyond White's abilities, they were well within Hariot's.

As the slide from Cyprian Lucar's A Treatise Named Lucar Solace (1590) shows, the plain table consisted of several parts. Its main component was the table itself, which was often made of three slats of wood that could be fitted together by means of grooves to make a flat, rectangular surface. Upon this surface, the surveyor would fit a piece of paper upon which to draw the map in the field using angular readings. The paper was held in place by the frame, which fit snugly around the four edges of the table. The four sides of the frame were often indexed or ruled off so that the surveyor could draw a grid of lines intersecting at right angles. The table was mounted on a stand that attached to the back of the table to hold it level to the horizon. Upon the table, on top of the paper, the surveyor placed a ruler, which, if it had a sight at each end, was called an alidade. The surveyor used this rule to sight distant objects along its length and to draw proportional lines on the paper to mark accurately the direction and distance of those distant objects using the method of triangulation (see slide 3). Lucar shows other traditional instruments used with the plain table, such as the two-legged compass to measure distance on the map and to draw accurate circles from the point of location and the right-angled square used to draw 90 degree angles. Also pictured is the "wyer line," which in the 1580s would have probably been a waxed and knotted cord used to measure physically the length of parts of the land being surveyed. The drum and stool in the illustration imply that the plain table developed from more informal instruments, the drum in particular pointing to the military influence on the development of surveying.

Bavin's instructions make clear the extent that he was to rely on his plain table to make his maps. He was told to draft his maps on sheets of "paper Royall" sized according to "the biggnes of the [plain] Table" (243) he was to take. He was then to begin by mapping the coast, sheet by sheet, marking each sheet with a letter from the alphabet (A, B, etc.) until the coast had been surveyed. After mapping the coast, he was to move inland, marking his sheets using double letters (AA, BB, etc.) so that he could determine how to join the sheets after the survey. These instructions make clear that Bavin was to conduct his survey and create the first draft of his map using the plain table and hence the method of triangulation. Since both the instrument and the method had become standard in England, Hariot and White probably used the same equipment and similar methods to map the Outer Banks.

Another surveying instrument that was well established by the time of Hariot and White's voyage was theodolite, which is pictured in this slide from the title page of Aaron Rathborne's 1616 The Surveyor. In England Leonard Digges first described this tool, which he named the "topographical instrument," in his posthumous A Geometrical Treastise Name Pantometria (1571), a book Hariot might well have known. Surveyors immediately adopted this instrument, which Humfrey Coles, one of the best English instrument makers of his day, constructed and sold. The theodolite allowed the surveyor to take readings simultaneously on the horizontal and vertical planes. Consequently, the surveyor could perform triangulation measurements to establish relationships between objects on the ground while at the same time measuring the height of vertical objects such as buildings, hills, or mountains. The theodolite was often used in conjunction with the plain table and was sometimes mounted on it. Since Bavin probably had such a combined instrument (his instructions mention "the Table of your Instrument," (243) suggesting that he had a plain table with a more complex instrument attached) (Taylor, "Instructions" 58), Hariot and White might have used one too.

As the slide suggests, the 16th-century theodolite was a fairly complex instrument. Rathborne's version consisted of a horizontal circle marked in degrees set upon a tripod. In the center of the circle was set a land compass to give direction, and this suggests that the instrument was made of brass, a metal that would not interfere with the magnetic needle. The compass allowed the surveyor to orient the instrument in the same direction every time he set it up. Above the horizontal circle was a vertical half circle that made a sight or alidade along its diameter. This half circle rotated, pulling along a pointer to mark degrees of arc on the horizontal circle and to determine the angles between distant points during the process of triangulation. The half circle also swiveled on the vertical to measure the angle of the height above the horizon of objects such as buildings and mountains.

Hariot and White's survey formed the basis for a number of important maps, but three of them-the preliminary sketch map, the map of the Outer Banks, and the composite map of the east coast from Florida to the Chesapeake Bay-remained in manuscript and were consequently not widely circulated. The map that received the widest audience is the one reproduced in this slide from Theodor de Bry's edition of Hariot's A Briefe and True Report, published in 1590 along with various water colors and one other map of the Outer Banks, focused more tightly on Roanoke Island, entitled "The Arrival of the Englishmen in Virginia."

De Bry apparently based his etching on a now lost White manuscript map. The map of the Outer Banks that de Bry etched contains many more topographical and hydrographical features than does White's extant manuscript map of the same region. These features include shoals and sandbars, rivers, hills, mountains, and trees, and their existence suggests that Hariot and White did indeed conduct a survey similar to Bavin's in which they noted important features. Although de Bry's map covers the same general coastal area as the manuscript map, it also extends a little less than 100 miles further inland, thereby showing topographical features not on the manuscript map and suggesting the potential value of the land to investors.

In addition to portraying topography and suggesting the potential value of the land, de Bry's map also symbolizes the contact between the native Americans and the English. Careful to show the Indians as peaceful, de Bry etches oversized figures clearly based on some of White's ethnographic Indian portraits. The most noticeable figure is the Indian warrior, standing in a stock mannerist pose holding his bow and arrow. It is important to note that the Indian looks peacefully at the ships approaching the shore and that his primitive weapons offer little threat to the English with their fire arms and cannon. The other picture, that of the Indian woman and her child, is a reversed reproduction based on another White portrait. It is significant that the child is playing with European toys, a rattle and a doll, because this suggests the potential value of the natives as trading partners.

The Hariot-White-de Bry map of the Outer Banks was one of the most important maps created of North America in the 16th century. As William P. Cumming, historian of American maps, comments, this map "became a prototype not only for maps of the Southeast but also, by the middle of the seventeenth century, for western hemispheric and world maps" (137). Its influence extended beyond its function as a map of a particular region largely because it set new standards for mapmaking in America. The primary reason for this importance was that the map began with Hariot and White's careful survey using the best instruments and techniques available to expedition surveyors at the time. Given the limited direct knowledge we have of the Hariot-White survey, we cannot determine with absolute accuracy how the two men went about their work. But knowing the instruments and techniques available to them supports the hypothesis that the striking accuracy of the Hariot-White-de Bry map was due to the application of mathematical instruments such as the cross staff, the compass and universal ring dial, the plain table, and perhaps the theodolite and the use of triangulation, which allowed the Renaissance surveyor to map out large tracts of land quickly and accurately.

1. Cross staff from Leonard Digge's A Booke Named Tectonicon, London, 1637.
2. Land compass and universal ring dial from E.G.R. Taylor's The Mathematical Practitioners of Tudor and Stuart England, Cambridge, 1954.
3. Method of triangulation from Arthur Hopton, Speculum Topographicum, London, 1611.
4. Plain table and equipment from Cyprian Lucar, A Treatise Name Lucar Solace, London, 1590.
5. Theodolite from Aaron Rathborne, The Surveyor in Foure Books, London, 1616.
6. Hariot-White-de Bry map of the Outer Banks from Theodor de Bry's French edition of Thomas Hariot's A Briefe and True Report of the New Found Land of Virginia. Frankfort, 1590.

Brown, Lloyd A. The Story of Maps. New York: Dover, 1977.

Excellent history of maps and their making.

Cumming, William P. Mapping the North Carolina Coast: Sixteenth-Century Cartography and the Roanoke Voyages. Raleigh, NC: North Carolina Department of Cultural Resources, 1989.

Essential discussions of early maps of North Carolina, with reproductions.

Greenhood, David. Mapping. Chicago: University of Chicago Press, 1964.

Good introduction for the novice to the theory and practice of surveying and mapmaking.

Harriot, Thomas. A Briefe and True Report of the New Found Land of Virginia: The Complete 1590 Theodor de Bry Edition. Ed. Paul Hulton. New York: Dover, 1972.

Contains the best inexpensive reproductions of the Hariot-White-de Bry maps.

Hulton, Paul. America 1585: The Complete Drawings of John White. Chapel Hill: Univ. of North Carolina Press, 1984.

The best inexpensive source for reproductions of White's work with an excellent introduction and commentary.

Hulton, Paul Hope, and David Beers Quinn. The American Drawings of John White, 1577-1590. 2 vols. Chapel Hill, NC: North Carolina Univ. Press, 1964.

Magnificent reproductions of White's drawings and de Bry's illustrations with a scholarly introduction to White and this work.

Humber, John L. Backgrounds and Preparations for the Roanoke Voyages, 1584-1590. Raleigh: North Carolina Department of Cultural Resources, 1986.

Good general discussions of the technical side of the voyages with useful pictures of surveying and cartographical equipment.

"Instructions for a voyage of reconnaissance to North America in 1582 or 1583." In New American World: A Documentary History of North America to 1612. Vol. III. Ed. David B. Quinn. New York: Arno Press, 1979, pp. 239-45.

Contains instructions to Bavin about surveying the American coast.

Keily, Edmund R. Surveying Instruments: Their History and Classroom Use. New York: Teachers College, Columbia University, 1947.

Excellent discussions of Renaissance surveying instruments and techniques.

Quinn, David Beers. Set Fair for Roanoke: Voyages and Colonies, 1584-1606. Chapel Hill: Univ. of North Carolina Press, 1985.

Important discussion of the Raleigh colonization movement in general with some attention to cartography, surveying, and navigation.

Richeson, A.W. English Land Measuring to 1800: Instruments and Practices. Cambridge, Mass.: M.I.T. Press, 1966.

Indispensable discussion of early English surveying theory and techniques.

Shirley, John W. Thomas Harriot: A Biography. Oxford: Clarendon, 1983.

Overdone but useful biography of Hariot, with attention to his background in mathematics and navigation.

Taylor, E.G.R. "Instructions to a Colonial Surveyor in 1582." The Mariner's Mirror, 37 (1951): 48-62.

The best scholarly discussion of Bavin's surveying instruments and methods.

——. The Mathematical Practitioners of Tudor and Stuart England. Cambridge: University Press, 1954.

Contains the best scholarly discussion of the development of surveying and mathematics in Renaissance England.