What was advertised in a colonial American newspaper 250 years ago today?

“Mathematical Instrument-Maker.”
William Williams, a “Mathematical Instrument-Maker,” kept a shop near the Long Wharf in Boston in the early 1770s. That location likely made it relatively easy for mariners to find him and purchase a variety of navigational tools, including compasses, sextants, and manuals. According to his advertisement in the May 16, 1771, edition of the Massachusetts Spy, he also stocked a variety of other item, such as “Gauging and Surveying Instruments,” “large and small Perspective Glasses in Ivory,” “hanging and standing Compasses in Brass and Wood,” and “Sand-Glasses, from two Hours to a Quarter of a Minute.” In addition, he carried some general merchandise, such as ink powder, jackknives, and “plated Shoe and Knee Buckles,” to supplement his more specialized inventory.
The most striking aspect of Williams’s advertisement, however, was not the list of items he offered for sale but instead the image of a well-dressed man holding a sextant, an instrument that measures the angle between an astronomical object, such as the sun, and the horizon for the purposes of celestial navigation. Few visual images appeared in the Massachusetts Spy at the time Williams placed his notice. One other advertisement included an image of a ship at sea, a woodcut that could have adorned many advertisements. Eighteenth-century printers tended to have many woodcuts depicting ships among the printing ornaments that advertisers could choose for their notices. The image of a captain holding a sextant, on the other hand, corresponded specifically to Williams’s occupation as a mathematical instrument maker. That woodcut did not belong to the printer. Instead, Williams commissioned it and retained sole authority to use it. Other advertisers did not have access to that particular woodcut, unlike the generic images of ships, houses, and horses that printers made available.
The depiction of a captain holding a sextant not only attracted attention on a page devoid of other visual images; it also immediately signaled what kind of enterprise Williams operated. In that regard, it served as a rudimentary logo that enhanced his marketing efforts and branded his business. Although some advertisers previously experimented with incorporating unique visual images into their newspaper notices, the practice gained popularity in the 1770s.