Benjamin King Hagger is listed in the city directory of Boston for 1798 as a "mathematical instrument maker" on Ann Street. This, however, is the last listing for his name in Boston, as his name does not appear in the 1803 or subsequent directories. Shortly after 1798 Hagger appears to have left Boston together with his wife, and it is probable that he established himself as an instrument maker in another Massachusetts community, at present unknown. In about 1816 Hagger moved with his family to Baltimore and continued his instrument-making business. The records of the 1850 Federal census of Baltimore indicate that two of Hagger's sons, John W. and William G. Hagger, had been born in 1800 and 1806 respectively, in Massachusetts, presumably in the community to which Hagger had moved from Boston before moving once more to Baltimore. According to Matchett's Baltimore directory for 1824, Hagger was a "mathematical and optical instrument maker" with a shop at 57 South Street. His advertisement in the directory stated that he Respectfully acquaints his fellow citizens that he executes all orders in the line of his business with punctuality and confidently professes to give satisfaction to his employers, from the experience of a regular apprenticeship and 37 years practice. This indicates that Hagger completed his apprenticeship in 1787, when he was 18, and since then had been established in his own business or had worked for another as a journeyman instrument maker. His first advertisement in the Boston directory appeared in 1789, wherein his shop was listed as being on Ann Street. Hagger died in Baltimore on November 8, 1834, at the age of 65, after a residence of 18 years in that city.[114] Thus far only one instrument by Hagger has been found--a wooden surveying instrument or semicircumferentor (fig. 59). It is in the possession of the writer. [Illustration: Figure 59.--Wooden graphometer made by Benjamin King Hagger (c. 1769-1834) of Boston and Baltimore. Made of yellow birch, with the name and gradations and lines incised into the wood by means of tiny punches, and filled. Trough compass; sighting bars mounted on a swivelling brass bar; collapsible tripod made of maple. In collection of the writer.] _Benjamin Warren_ [Illustration: Figure 60.--An advertisement of Benjamin Warren in _The Plymouth Journal & Massachusetts Advertiser_. Photos courtesy The American Antiquarian Society, Worcester, Massachusetts.]