32 
WiLLiAMs_, on the Martin Microscope. 
Astronomical Society tliere are nineteen of his works^ and 
from incidental notices in tliese^ I have been enabled to add 
considerably to the scanty mention of him in works on gene- 
ral biography. Thiis_, Martin does not appear to have been 
originally an optician_, for in one of his early works on Trigo- 
nometry he dates his preface " From my school in Chichester, 
April 8, 1734;" and an advertisement in the same work 
announces that, "By the author in Chichester are taught, 
1. Writing in all the common and useful hands: 2. Arith- 
metic," and so on, enumerating various other accomplish- 
ments taught by him, to 16. The use and construction of 
all the most useful mathematical instruments ;" and the ad- 
vertisement concludes with " N.B. Youths are boarded very 
reasonably by the author, Benjamin Martin." We find him 
here, then, as a schoolmaster in Chichester. His ^ Bibliotheca 
Technological is also dated from Chichester, 1740. In this 
he styles himself " Teacher of the Mathematics and in his 
^ New and Compendious System of Optics, printed for James 
Hodges, at the Looking Glass, on London Bridge,^ the follow- 
ing advertisement occurs : — "New-invented pocket reflecting 
Microscopes, with Micrometers, made and sold by Benjamin 
Martin, in Chichester, at the following prices, viz., those with 
a micrometer, at one guinea; without a micrometer, at ten 
shillings and sixpence." It goes on enumerating the good 
qualities of these microscopes, and concludes by stating that 
" they may be obtained by application at the British Coff'ee 
House, Finch Lane, London, or sent to any part of England 
by a letter to me at Chichester. Allowance will be made to 
those who take a quantity." It might be of some interest 
could we ascertain the kind of instrument here advertised for 
sale. By a " reflecting microscope," I presume Martin refers 
to one in which the light is thrown upon the object by reflec- 
tion ; in other words, by means of a mirror, in contradistinc- 
tion to those constructed upon the principle of "Wilson^s 
Pocket Microscope," a form which was at that time exceed- 
ingly popular, and which required holding up to the light 
when in use. In one of his works, Martin figures and de- 
scribes an instrument which he calls a pocket microscope," 
to which a micrometer is attached ; and at Mr, Quekett's sale 
a small microscope with Martinis name upon it, answering to 
this description, but without a micrometer, was purchased by 
Mr. Boper. In all probability this is one of the same de- 
scription as that referred to in the advertisement I have just 
quoted. 
It is not unlikely he found the making and selling of 
microscopes more profitable than the scholastic profession, 
