229 



EARLY MICROSCOPES. 



T. SHEPPARD, F.G.S. 



In connection with the system adopted at the Hull Museum, 

 of illustrating the growth and evolution of the various exhibits, 

 whether they are spinning-wheels, bicycles, lighting appliances 

 or corsets, an opportunity has recently occurred of showing a 

 series of instruments illustrating the evolution of the microscope. 





Fig. I. 

 •Screw-barrel' Microscope, circa 1735. 



The specimen shown in the first illustration is a pocket 

 microscope, which dates to the early part of the eighteenth 

 century, probably about 1725. A similar one is figured in 

 George Adams' ' Micrographia illustrata,' 1746, plate V., figure 

 6. In that work the microscope is referred to as the * screw 

 barrell ' or ' Mr. Wilson's single pocket microscope,' and it is 

 there stated that this microscope of Mr. Wilson's is an inven- 

 tion of many years' standing. It will be seen that the micros- 

 cope is focussed by means of a large threaded screw, which 

 feeds into the butt of the instrument, and the objects are in- 

 serted through the stage, and held in position by means of a 

 wire spring. The instrument is held in the hand by a turned 



igia Aug. I. Q 



