Answers to Queries. 233 
414.—Forming Cells.—Holes may be drilled through thick 
glass by means of a hard-pointed drill moistened with turpentine. 
The method recommended by Beale is good. A piece of thin 
glass is cemented to a ring or circle (used for making deep cells) 
with marine glue. When cold, a file is pushed through the 
centre. The cracks do not extend through the marine glue. 
The edges are filed square, and then the thin glass is warmed and 
removed. It may be cleaned by means of potash. 
J. A. Hoae. 
415.—Drawing Micro Objects.— Vide answers to 379 in the 
October Scientific Enquirer. It is hard to say which is the dest 
instrument for drawing microscopic objects, but there is no doubt 
about the cheapest, and that is Beale’s form, as it can be easily 
made at home as follows :—If the eye-piece has a cap, remove it 
and make a cardboard tube to fit over it, in place of the cap; if 
the ocular is of the foreign form, a cardboard or paper tube must 
be made to fit over the body of the microscope, so as to bring it 
flush with the rim of the eyepiece, and a cardboard tube made to 
fit over the body. Cut one end of the tube at an angle of 45° 
with its axis, like an ordinary mitre joint, and fix on this another 
flat piece of card, with a hole in the centre. Over this hole fix a 
thin cover-glass, and above this cover-glass cut a fair-sized hole in 
the cardboard tube. Make the tube of such a length, that when 
pushed home the edge of the cover-glass will about touch the 
eyepiece. Blacken the inside with ink or paint (a couple of visit- 
ing cards and some gummed paper will do all this work). The 
objection to this form is that it reverses the objects. Another way 
of drawing is by means of a piece of glass ruled in squares, 
known as a net-micrometer, which is placed on the top in the eye- 
piece. ‘The drawing is done by hand on a piece of paper ruled in 
squares. Very good work can be done by this method, and the 
instrument also forms a very convenient eye-piece micrometer. 
These net-micrometers cost from 4/- JG. PP) VEREKER: 
415.—Drawing Micro Objects.—I have always used Beale’s 
neutral-tint glass, and find it a very useful little instrument. The 
main difficulty is with the light, and it is only by practice that one 
is able to get the proper illumination. The object appears to be 
thrown on the paper, and the size of the sketch may be varied by 
bringing the paper nearer to or further from the eyepiece. The 
paper is usually placed at ten inches distance. A simple substi- 
tute, invented by an American, Mr. Jennings, may be interesting. 
Take a flat cork, 1} inches in diameter, through which cut a hole 
so large as to fit on the eyepiece without the cap. Then make a 
transverse slit beneath the hole, in which place a glass cover 
inclined at an angle of 45°. J. A. HoGe. 
