BAUSCH AND LOME'S PORTABLE MICROSCOPE 



247 



folds. It is provided with sliding tube, coarse, and micrometer 

 screw fine adjustments, a good draw-tube and thoroughly useful 

 stage, a tubular sub-stage with plane and concave mirrors. It is 

 packed in. a leather case with shoulder strap and loops for a 

 military belt, or a handle, and this case, with three objectives 

 and extra eye-piece, occupies 11 x 8-5 x 3 inches. It can also 

 be arranged for a sub-stage carrying a condenser and iris dia- 

 phragm, and is exceedingly compact and well made. 



A very old device has been utilised by Messrs. Bausch and Lomb 

 for a new portable stand, that, namely, of making the case or box the 

 foot of the instrument. The microscope itself is, in every other respect 

 save size, the same as their ' New ' stand shown in fig. 193 ; but the 

 addition is made of a clamping screw, to prevent the main tube from 



FIG. 199. Bausch and Lomb's portable microscope packed (1898). 



dropping or turning. An illustration of this microscope is given, as 

 set up for use, in fig. 198. It will be seen that a double nose-piece 

 may be used, and it is provided w T ith a useful condenser, the sub- 

 stage having a screw focussing adjustment, and an arrangement for 

 swinging this out of the optic axis. The microscope is rigid, but 

 can be inclined at any angle by raising the cover of the case as in 

 the figure. It can be closed into the box with its double nose- 

 pieces in position, and its sub-stage and condenser ready for use. 

 The size of the case complete is 8| x 5| x 2^ inches, and its weight 

 is 3f pounds. 



Microscopes employed for the purpose of minute dissection are 

 of considerable importance in certain kinds of work. Many instru- 

 ments specially adapted are made, although the majority are 

 arranged for simple lenses. But an instrument of great value, 



