To make a comprehensive study of American scientific instruments and instrument makers in the American Colonies is no simple matter, partly because of an indifference to the subject in the past, and partly because of the great volume of sources that must be sifted to accomplish it. Such a project would require an organized search of all published reference works relating to the field and associated topics, of all contemporary newspapers for advertisements and notices, of civil records filed in state and community archives, of business account-books and records that have been preserved, and of business directories of the period under consideration. In addition, such a study would require the compilation of an inventory of all surviving instruments in private and public collections, and a correlation of all the data that could be assembled from these sources. The present study attempts only in part to accomplish this aim, being no more than a preliminary compilation of the scientific instruments known to have been used during the first two centuries of American colonial existence. It merely attempts to assemble all the data that is presently available in scattered sources, and to organize it in a usable form for the student and historian of American science. A supplement relating to 19th-century instruments and instrument makers is in progress. The most that is hoped for the present work is that it will be of temporary assistance, serving to bring forth additional information on the subject from sources not previously available or known. _February 1, 1964_ S.A.B. EARLY AMERICAN SCIENTIFIC INSTRUMENTS _and Their Makers_ _The Tools of Science_ Philosophical and Practical Instruments Development of the sciences in the American Colonies was critically dependent upon the available tools--scientific instruments--and the men who made and used them. These tools may be separated into two groups. The first group consists of philosophical instruments and scientific teaching apparatus produced and employed for experimentation and teaching in educational institutions. The second includes the so-called "mathematical instruments" of practical use, which were employed by mathematical practitioners and laymen alike for the mensural and nautical needs of the Colonies. It is particularly with this second group that the present study is concerned. It has been generally assumed that scientific instruments, as well as the instrument makers, of the first two centuries of American colonization were imported from England, and that the movement declined by the beginning of the 19th century with the development of skilled native craftsmen.[1] This assumption is basically true for those instruments grouped under philosophical and scientific apparatus for experimentation and teaching. Almost all of these items were in fact imported from England and France until well into the 19th century.