Mathematical notebook attributed to Thaddeus Mason Harris, ca. 1787

Hardcover notebook containing handwritten transcriptions of rules, cases, and examples from 18th century mathematical texts. The author and purpose of the volume is unclear, though it has been connected with Thaddeus Mason Harris (Harvard AB 1787). Most of the entries include questions and related answers, suggesting the notebook was used as a manuscript textbook and workbook. The extracts appear to be copied from John Dean's " Practical arithmetic" (published in 1756 and 1761), Daniel Fenning's "The young algebraist's companion" (published in multiple editions beginning in 1750), and Martin Clare's "Youth's introduction to trade and business" (extracts first included in 1748 edition).

Arithmetic copybook : manuscript, [17--]

Arithmetic copybook containing mathematical rules, problems, proofs, and charts of weights and measures.

Treatise on mathematics and astronomy: written about the year 1680, in Boston

Bound volume containing a late 17th century handwritten mathematical and astronomical text in one hand. The text is separated into mathematical and astronomical sections with rules, instructions for performing calculations, tables, and drawings. The subjects include arithmetic, geometry, astronomy, and trigonometry, and segments have titles such as "Subtraction," "A decimal table of English coince," "Logarithes & their use," and "To find the true place of the sun." The text is undated and unattributed but references Briggs, Oughtred, Ramus, and Apollonius. Certain tables are calculated from latitudinal and longitudinal numbers associated with Boston, and many of the examples use dates in the 1670s and 1680. The manuscript pages are mounted onto unruled pages, and some of the manuscript pages are fragments.