APPENDIX II ~ 368 
Tools for the manufacture and repair of apparatus will be found 
almost indispensable in the laboratory. Among the most useful are 
round files for cork-boring and triangular ones for cutting glass, a 
hammer, nails and brads, fine carpenter’s saw, hack-saw, pliers and 
cutting pliers, chisels, brace with bits and twist drills, annealed brass 
wire, small soldering copper with solder and zinc-chloride soldering 
solution. 
The Compound Microscope. — Compound microscopes and acces- 
sories may be bought of most dealers in physical apparatus. Four 
of the most important manufacturers are the Bausch & Lomb Optical 
Co., Rochester, N.Y.; E. Leitz, 30 East Eighteenth St., New York 
City; the Spencer Lens Co., Buffalo, N.Y.; and C. Zeiss, represented 
by the Bausch & Lomb Co. All send catalogues on application, and 
all furnish instruments suitable for high-school laboratories at prices 
ranging from $20 to $35. The microscopes of German manufacture 
(of Leitz and Zeiss) are imported duty free for schools. 
A very brief account of the construction and use of the compound 
microscope is given in the Manual, pp. 10-14. More details can be 
found in Winslow’s Elements of Applied Microscopy, John Wiley & 
Sons, N.Y., or in any of the standard treatises, such as Gage’s, or 
Carpenter and Dallinger’s. 
School microscopes are very commonly provided with a 2-inch 
and a l-inch eyepiece and a 2-inch and }-inch objective. In this 
case either eyepiece when used with the lower objective will give 
alow power. The 2-inch eyepiece with the 4-inch objective will give 
a medium power, and the l-inch eyepiece with the 31-inch objective 
will give a moderately high power. 
It will be found desirable to equip many if not all of the stands 
also with a 2-inch objective, as this gives a far better general view 
of such objects as sections of roots or stems of seed plants, green 
alge, small liverworts, fern prothallia, and so on than can be ob- 
tained with a hand lens. If possible, the laboratory should have at 
least one stage micrometer, several eyepiece micrometers, and a cam- 
era lucida. The micrometers should be kept in frequent use to give 
the students accurate ideas of the dimensions of objects studied, 
and the camera lucida should be used as a check on the accuracy of 
drawings made from the microscope without it. 
