232 THE HISTORY AND DEVELOPMENT OF THE MICROSCOPE 



foot when the instrument is in an upright position. When inclined, 

 the centre of gravity is again brought directly over the foot, as 

 shown in fig. 185, by rotating the pillar upon a reliable fitting at 

 its base, so that absolute steadiness is secured. This is a revival 



FIG. 185. Boss's new bacteriological microscope (1894). 



of an old form made in 1760 by J. Cuff, adapted by A. Ross in 

 1842, and now again used by the same firm (vide fig. 128). 



Ross also manufactures an ' Educational ' microscope having 

 considerable merit, which may fairly be placed in this class. It 



