knowledge of land surveying was a useful skill, and many a boy learned its elements by following the 'boundsgoer' in his work of 'running the line.' And those who did not actually take part in running the line must have attended many a gay springtime 'processioning' when neighbors made a festive occasion out of 'perambulating the bounds'." "Vague land grants and inaccurate surveys," he adds, "made the subject of boundary lines a prime issue in the everyday life of colonial homes."

At the same time there was interest in the other aspects of the mathematical sciences. As early as 1743, for instance, a Harvard mathematician named Nathan Prince advertised in Boston that if he were given "suitable Encouragement" he would establish a school to teach "Geography and Astronomy, With the Use of the Globes, and the several kinds of Projecting the Sphere" among other things.[6] A decade later, Theophilus Grew, professor in the academy at Philadelphia which has become the University of Pennsylvania, published a treatise on globes, with the title:

The Description and Use of the Globes, Celestial and Terrestrial; With Variety for Examples for the Learner's Exercises: Intended for the Use of Such Persons as would attain to the Knowledge of those Instruments; But Chiefly designed for the Instruction of the young Gentlemen at the Academy in Philadelphia. To which is added Rules for working all the Cases in Plain and Spherical Triangles without a Scheme. By Theophilus Grew, Mathematical Professor. Germantown, Printed by Christopher Sower, 1753.[7]

Thus, the need for practical mathematical instruments for the surveyor and navigator became critical in proportion to the need for men to make and use them, and it is not surprising to discover that the majority of the instruments produced and advertised by early American makers were for surveying, with nautical instruments in second place. Generally, the surveyors were not professionals; they were farmers, tradesmen, or craftsmen with a sound knowledge of basic arithmetic and occasionally with some advanced study of the subject as taught in the evening schools. The surveying of provincial and intercolonial boundaries required greater skill, however, as well as a knowledge of astronomy, and this work was relegated to the scientific men of the period.

As the increasing preoccupation with subdivision of land and with surveying led to a greater demand for suitable instruments, it was the skilled craftsmen of the community, such as the clockmaker and the silversmith, that were called upon to produce them. Superb examples also were produced by the advanced scientific men, or "mathematical practitioners," of the period.

Colonial Training in Instrument Making

One may well ask, where did these native craftsmen acquire the knowledge that enabled them to produce so skillfully the accurate and often delicate mathematical instruments? There were a number of possible sources for this knowledge. The first source lies in England, where some of these craftsmen could have studied or served apprenticeships. After completing their apprenticeship with English mathematical practitioners, they may have immigrated to the Colonies and taught the craft to others. This seems to be entirely plausible, and was probably true, for example, of Thomas Harland the clockmaker, Anthony Lamb, and perhaps several others. However, these were the exceptions instead of the rule, since a biographical study of the instrument makers in general reveals that they were for the most part native to America. It is not likely that the one or two isolated practitioners that had been trained in England could have taught so many others who worked in the same epoch.

Another source for this knowledge of instrument making was probably the reference works on the subject that had been published in England and in France. As an example, Nicolas Bion's Traitè de la Construction et des Principaux Usages des Instruments de Mathematique, which had been first published in 1686, was translated into English by Edmund Stone in 1723, and went into several English editions. Copies of this work in English undoubtedly found their way to America soon after publication. Other popular works were Aaron Rathbone's The Surveyor, which appeared in London in 1616 (see fig. 2); William Leybourn's The Compleat Surveyor, in 1653; and George Atwell's Faithfull Surveyour, in 1662. Other works popular in the Colonies were R. Norwood's Epitome, or The Doctrine of Triangles (London, 1659) and J. Love's Geodasia, or the Art of Surveying (London, 1688).

These works undoubtedly inspired similar publications in America, for many books on surveying and navigation appeared there before the beginning of the 19th century. Chief among them were S. Moore's An Accurate System of Surveying (Litchfield, Conn., 1796), Z. Jess's A Compendious System of Practical Surveying (Wilmington, 1799), Abel Flint's Surveying (Hartford, 1804), and J. Day's Principles of Navigation and Surveying (New Haven, 1817).

The published works were unquestionably responsible for much of the training in the making of mathematical instruments in America, although no documentary evidence has yet been recovered to prove it.

Another important influence on early American instrument-making which must be noted was that of the clockmaker as an artisan. A comprehensive study of surviving instruments and related records has revealed that only a few of the many clockmakers working in the American Colonies in the 18th century made mathematical instruments. Yet, a large proportion of the surviving surveying and nautical instruments produced before 1800 were the work of clockmakers. Classic among these must be noted the instruments produced by the brothers David and Benjamin Rittenhouse (see p. 15 and figs. 3 and 4), as well as the fine surveying instruments made by four separate members of the Chandlee family, whose clockmaking traditions began early in the 17th century (see p. 54).