1895 THE MICROSCOPE. 171 



bend the wire downward, at right angles, sharply, about 

 four inches from the loop (fig. 3). This angle should be 

 squared with a file. Now place the lens (fig. 7) over the 

 center of the stage and at a point where the end of the 

 wire touches the top of the box — toward the right — 

 mark the place for the adjusting post. This is made of 

 two pieces of brass tubing or gas pipe so cut with fine 

 threads that one may be screwed into the other half or 

 three-fourths of an inch (fig. 4), the outer piece of the 

 two is now tightly fastened into a hole made at the j)oint 

 touched by the end of the wire, the inner is screwed into 

 place and the wire is dropj^ed into the hole through both, 

 resting at its angle upon the upper edge. As the upper 

 piece is turned, the wire carrying the lens is raised or 

 lowered and is capable of very nice adjustment. 



One thing more remains to be done. It will be noticed 

 when the upper part of the adjusting post is turned the 

 lens arm swings back and forth. This is overcome by 

 taking another piece of the brass wire and making a long 

 staple (fig. 5) to serve as a guide for the arm, the inner 

 measurement of the staple is the same as the dia- 

 meter of the arm wire, so that no motion is lost. 

 This is secured in place by boring holes in the top of the 

 box, the proper distant apart and forcing the legs of the 

 staj^le into them. One finds plenty of room to work on 

 this stage and ample rest for the hands. For dissecting 

 use the ordinary handled needles and make one more by 

 forcing the eye end of a good large needle into a pen 

 stick, on a grindstone flatten two opposite sides for about 

 half an inch from the point and continue grinding till a 

 nice cutting edge is made, get this well sharpened and you 

 have a most useful dissecting needle-knife. — Graduate. 



Light. — The flame of the lamp used with the microscope 

 may be intensified and improved by placing in the oil a small 

 piece of gum camphor. The flame is thus rendered whiter and 

 very brilliant. It is a good thing to do when resolving difficult 

 diatoms. 



