OBSERVING WITH AND MANAGING ENGTSCOPE. 209 



smaller aperture of this, and proceed. I should recom- 

 mend you to get the leaves of two Pembroke or other 

 tables placed on each side of you, to rest your elbows 

 upon at pleasure, and likewise to procure several pieces 

 of board, about one and a half inch thick, to place under 

 the instrument, to depress or elevate it without the help 

 of the slide in the pillar (which, when called into effect, 

 always unlocks the bar.) 



Your operations can always be carried on under the 

 surface of liquids, by the help of the direct or diagonal 

 boots. 



When you wish to get at the side of your subject with- 

 out disturbing its surface, mount in the position, No. 2, 

 and turn your stage round on the pivot, i, until it comes 

 to be in the plane of the bar : every lateral view can then 

 be obtained at pleasure, by turning the object round, 

 and you can operate in this position as well as in the ver- 

 tical one. You may also, by help of the ball and socket, 

 tilt the body at any required angle, and still adjust the 

 stage to the horizontal position, as before, taking care to 

 pinch it fast by means of the screw, /, before you begin 

 to work again. 



There are no tools for dissection equal to very fine 

 scissars,they always cut without dragging or tearing ; 

 there is, however, the greatest difficulty in procuring 

 them. The Sheffield workmen are the only ones capable 

 of making them sufficiently delicate. Miniature scissars 

 have been made only half an inch in length quite perfect; 

 now, a pair constructed with blades like these, but io 



p 



