200 MICROSCOPIC OBJECTS. 



strength of the material employed. The stand I am 

 now going to describe is of a very simple naiure; yet it 

 might perhaps give satisfaction to many observers with 

 ordinary engiscopes having high powers. It is made of 

 metal, and on a small scale. Fig. 1 (p. 195), ^ is a hinge or 

 cradle -joint, with a long neck made of sycamore or any 

 other close-grained wood, and of course suf&ciently sub- 

 stantial ; the tube, /, into which the body is inserted, is 

 lined with brass in the inside, like the first joint of a 

 spy-glass, and moreover strengthened by two ferrules 

 k, k, on the outside, which are screwed to the interior 

 tube. The neck is hkewise strengthened by a piece of 

 veneer, h, let into it, so that its grain shall cross at 

 right angles that of the recipient part, into which it is 

 carefully glued. Tlie inserted piece must not be too 

 thick, or it will give the joint a tendency to warp. The 

 two external cheeks of the hinge are of the same thick- 

 ness and strengthened in the same manner. A brass 

 washer is placed on each side, and a metallic screw 

 passed through the whole. The joint may be put 

 together with a little chalk, or with powdered resin if 

 not stiff enough, or with black lead, or some of that 

 magnesian fossil called mountain soap,* or French chalk, 

 similar to that used to make pencils to wTite on glass, if 



* A German organ-builder once showed me a substance which 

 he said answered admirably for smearing the stops of his instru- 

 ment, as it gave all the lubricity of black lead without being 

 amenable to the action of the weather as black lead is. He knew 

 not what it was ; but I think it was that magnesian fossil called 

 mountain soap. 



