Fig. 13. Ellis Aquatic Microscope, Inventorj^ 1911-294, in the Science Museum, London. 

 The Museum description states: "This type of microscope may be regarded as the 

 precursor of the most complete and perfect of our simple dissection microscopes, 

 and it was made with slight modifications by all the leading opticians until the 

 early years of the 19th century. . . . The round hollow pillar screws into a socket 

 in the lid of the fish-skin case. The mirror mounted in gimbals is fitted to the pillar 

 by a spring-pin and socket. The inner sliding rod which carries the objective arm 

 can be fixed at the desired height by a clamping screw. The stage is removable for 

 portability, and a Wilson screw barrel microscope with three additional powers is 

 added, which can be adapted to the stand". (Photograph British Crown Copyright. 

 Science Museum, London.) 



