WiLLiAMSj on Benjamin Martin. 
3 
dealing in a sort of glass too bad for any bnt themselves to 
recommend^ or for any one to buy who knows anything of 
optical glass_, or has more regard to the safety of his eyes and 
the preservation of his sight than the saving of his money/' 
In the same work is given A Catalogue of Philosophical, 
Optical^ and Mathematical Instruments^ made and sold by 
Benjamin Martin, at his shop, the sign of Hadley's Quadrant 
and Visual Glasses, near Crown Court, Fleet Street/'' The 
prices are mentioned, and among them we find, Large 
parlour compound microscope, £3 13s. 6d. ; ditto, in brass, 
£5 5s. j solar microscope, £5 5s. ; Wilson's ditto, with appa- 
ratus, £2 12s. 6d. ; ditto, small, £l 7s. ; Dr. Lieberkuhn's 
opaque microscope, £2 12s. 6d. ; ditto ditto, £3 13s. 6d. ; 
aquatic microscope, £2 12s. 6d. ; universal compound micro- 
scope, £5 5s. ; pocket compound ditto, £2 2s/' This list is 
curious, as showing the cost of various microscopes at that 
time. 
Martin also published a few prints, of which a list is given : 
They were — ' Synopsis of Celestial Science,' Is. 6d. ; ^ Orbit of 
Comet of 1682 and 1759,' Is. 6d.; ^Wonders of Cometary 
World Displayed,' 2s. 6d.; 'New Map of the World,' Is. 6d.; 
'Map of 460 Miles round London,' 6d.; 'Map of 20 Miles 
round London,' 6d. ; Transit of Venus over the Sun, January 
6th, 1761,' Is. 6d. 
In conclusion, I append a list of works published by Martin 
between 1733 and 1773, a period of forty years, which I 
have endeavoured to render as complete as possible. They 
amount to forty, and are: — 'Philosophical Grammar' (the first 
of his works); ' Elements of Geometry,' 1733 ; 'Spelling-Book 
of the Arts and Sciences, for the use of Schools;' 'Decimal 
Arithmetic,' 1735 ; 'Young Student's Memorial Book,' 1735; 
'Description of the Globes,' 2 vols., 1736; 'Memoirs of the 
Academy of Paris,' 1740; 'Panegyric of the Newtonian 
Philosophy,' 1734; ' On the New Construction of the Globes,' 
1755; 'System of the Newtonian Philosophy,' 1759; 'New 
Elements of Optics,' 1759; 'Mathematical liastitutes,' 1759- 
64; 'The Natural History of England,' 1759; 'Biographia 
Philosophica,' 1764; 'Introduction to the Newtonian Phi- 
losophy,' 1765; ' Institutions of Astronomical Calculations,' 
1765; 'Description and Use of the Air-pump,' 1766; 'De- 
scription of the Torricellian Barometer,' 1760; 'Appendix to 
Description of the Globes,' 1766; 'Philosophia Britannica,' 
3 vols., 1773; 'Philosophical Magazine and Miscellaneous 
Correspondence,' 14 vols.; 'New Principles of Geography 
and Navigation,' 1758; 'Familiar Introduction to Experi- 
mental Philosophy;' 'The Transit of Venus Explained;' 
