230 



Sheppard \ Early Microscopes. 



ivory handle. There are six lenses of various magnifying 

 powers, protected by small ivory domes. There is also an 

 arm, a forceps, and some small ivory slides, each of which holds 

 four objects. There is a small box containing talc covers for 

 the sides, and portions of elytra of beetles, etc., which were 

 the favourite objects for examination. This very interesting 

 series of specimens, complete in a shagreen case which mea- 

 sures 7I inches long by 2f inches wide, has been presented to 

 the museum by Mr. T. Audas, L.D.S. It previously belonged 



to three generations of the 

 Harrison family, one of 

 whom, Robert, was a well- 

 known microscopist early 

 last century, and was the 

 discoverer of the diatom, 

 Odontidium harrisonii. This 

 Robert Harrison was at one 

 time curator of the museum 

 of the Literary and Philo- 

 sophical Society at Hull, 

 which is now merged into 

 the Municipal Museum, and 

 in the building is a magni- 

 ficent marble bust to his 

 memory. 



The accompanying illus- 

 tration (fig. 2) is taken from 

 George Adams' ' Micro- 

 graphia illustrata," 1746, 

 and well illustrates the 

 parts of this interesting 

 instrument. The following 

 description is as given by 

 Adams : — 



Fig-. 2. 



Screw=barrell ' Microscope, as figured in 

 Adams' Micrographia illustrata, 1746. 



AB— The body. 



CC. — Fine threaded male screw. 



D. — Convex glass on which may be placed as occasion 

 requires, concave pieces of thin brass with holes 

 of different dimensions in their centres to cover 

 the glass and diminish the aperture. 



EF— Brass plate, one of which is bent to receive a glass 

 tube (to confine living objects). 



G — Hollow female screw to receive the magnifiers. 



H — A spiral spring of steel to keep the objects in position. 



I — A handle. 



K — One of the seven different magnifying glasses. 



L — The seventh magnifier, which can be used in the hand. 



Naturalist, 



