8 HOW TO USE THE MICROSCOPE 



supplied by Messrs. Watson. This instrument is 

 made of mahogany ; the slope of the sides affords 

 convenient support to the hands ; the removable 

 stage, 44 inches square, is of glass ; the arm for 

 carrying the lens is raised or lowered by a spiral 

 rack-and-pinion adjustment ; and light is trans- 

 mitted through the glass stage by means of the 

 mirror beneath. The cost, Avithout lenses, is £2. 

 With a sliding bar instead of rack-work, the cost 

 is reduced to £1 5s. But the worker who does not 

 feel able to afford such an instrument need not on 



Fig. 8. — Watson's "Laboeatoey" Dissecting Mioeoscopb. 



that account go without one that will yield satis- 

 factory results. A piece of glass let into a suitable 

 opening in the side of a cigar-box will form a stage ; 

 a mirror fixed at an angle of 45 degrees below it 

 will reflect light through a sufficiently transparent 

 object placed on the stage ; and the arm holding the 

 lens may be made to slide, for focussing purposes, 

 on a suitable upright. Nor is there any reason why 

 a mirror should not be fixed on a moving fitting; so 

 that it may be made to reflect light through the 

 stage at various angles. 



It should be added that cheaper dissecting micro- 



