ZOOLOGY AMI BOTANY, .M I(JR()SG(M'V, ETC. 651 



the help of a very commodious Microscope of Cuff's, the optician in 

 Fleet Street, luhich I had altered for the purpose." 



Ellis's Aquatic Microscope is also hgured in George Adams' Micro- 

 graphia Illustrata 1771, and is of a simple type for use with low powers. 



Old Microscope by Watkins and Smith.* — In November 1907 

 E. M. Nelson described l)efore this Society an old Microscope (date 

 between 1765-1775) made entirely in solid silver by Francois Watkins, 

 an Anglo-Frenchman, of Charing Cross, London, who published a small 

 book in French entitled L'Exercice du Microscope, London, 1754-5, 

 a copy of which is in our iilirary. 



Through the investigations of T. H. Court, who has searched Kent's 

 London Directories of the latter half of the eighteenth century, we now 

 know that Francois Watkins in 1754 was "Optician to their Royal High- 

 nesses Prince and Princess of Wales at Sir Istiack Newton's Head, Charing 

 Cross." In 1765 the name of the firm appears to have been changed into 

 that of Watkins and Smith, and can be traced through the Directories 

 until 1774. In or about 1775 Smith appears to have died or retired, and 

 the firm was again carried on by F. Watkins alone, as indicated by the 

 Directory of 1776 and subsequent years. Watkins seems to have died, 

 or else retired, al)out 1700. In 171)6 the firms' style was T. and W. 

 Watkins, and in 1806 Watkins and Hill. 



The old Microscope (fig. 121) here exhibited by the kindness of T. H. 

 Court is signed Watkins and Smith, and was therefore made between the 

 years 1765-1775. It has much resemblance with the silver Microscope 

 described by Nelson, but is more substantially made in every way, and the 

 folding tripod-foot is strong enough to prevent vibration, thus correcting 

 most of Nelson's adverse criticism of the silver Microscope. The screw 

 fine-adjustment at the base of the limb of the latter has been removed, 

 and replaced by a very good and strong sprung-rack coarse-adjustment 

 which moves the stage, thus changing the model from a body-focuser to 

 a stage-focuser. As Nelson has stated, Watkins' earlier Microscope has 

 introduced some improvements of first-rate importance, such as the in- 

 clinable limb to carry the body, stage and mirror, and in the present 

 specimen an excellent rack-and-pinion movement to the stage, with the 

 rack cut in the back of the liml). The stage can be removed by pressing 

 a lever. The seven powers are mounted on a wheel l)etween two brass 

 plates, and can be used as simple Microscopes or with a body and eye- 

 piece as a compound (or double) Microscope. The limb is marked with 

 a double set of numbers S and D, indicating the position of the stage 

 correspondins: with the focus of the power in use, both for the simple 

 and double Microscope. The limb is made inclinable by a compass-joint 

 and can ])e fixed in any position by means of a thumb-screw. The mirror 

 is double, plane and concave. The compound body unfortunately is lost. 

 In the same box with the Microscope is a solar projection apparatus, 

 identical with that described by Nelson for the silver model. 



Old Culpeper and Scarlet Microscope by George Adams. — The 



old Microscope depicted in fig. 75, p. 445, is a large specimen of the 

 Culpeper and Scarlet type of " doul)le reflecting " Microscope made by 



* See this Journal, 1908, pp. 137-45. 



