654 SUMMARY OF CURRENT RESEARCHES RELATING TO 



CULPEPER AND SCARLET. Invented about 1738. 



Type — Compound, uncorrected. 



This tripod form of Microscope stand, mounted on a wooden box. 

 was a favourite model for more than a century. It was copied and 

 made by successive opticians with many variations in form, material, 

 and finish until about the middle of last century. The body of the 

 present model is made of wood and cardboard, and the focusing is done 

 by sliding the body. There is no fine-adjustment. The object-glass is 

 a single biconvex lens, and the eye-piece has two lenses. A mirror 

 with ball-and-socket motion is fixed to the box foot. 



This instrument is described in R. Smith's " Opticks " (Cambridge,. 

 1738), ii. p. 407, and figured in Mayall's Cantor Lectures, 1885, p. 40. 



NATHANIEL ADAMS. About 1740. 



Type — Compound, uncorrected. 



This is of the Culpeper and Scarlet pattern, and is rendered even 

 more unhandy than its original by the addition of a fourth pillar in the 

 space surrounding the stage. This inconvenience was incurred, no 

 doubt, for the sake of the greater rigidity secured by the fourth pillar 

 — a distinct advantage in focusing the instrument. Attention may be 

 drawn to the elaborate chain of ball-and-socket joints by which a 

 condensing lens is connected to the stage. 



Presented to the Society May 17, 1905. See Journ. R.M.S., 1905, 

 p. 397. 



DOLLOND. About 1816. 



Type — Compound, uncorrected. 



This again is of the Culpeper and Scarlet pattern, but shows a great 

 advance in its mechanism, being made all in brass and fitted with a 

 rack-and-pinion focusing arrangement. This specimen is remarkable 

 for its date as showing the persistence and continued improvement of 

 an obsolete type of instrument at a time when instruments of a much 

 better design were being produced. 



Described in the Journ. R.M.S., 1901, p. 227. 



JOHN CUFF'S "Single" and "Double" Aquatic Microscope. 



Date about 1760. 



Type — Alternatively Simple or Compound, uncorrected. 



Compared with its predecessors, and in particular with instruments 

 of the Culpeper and Scarlet model, the present instrument show& 



