THE YOUNG SCIENTIST. 
151 
Soldering Broken Files. 
A writer in the English Mechanic, who had 
broken the only half-round file he had by him, 
says: "After trying to use the broken end (it 
was broken about the middle), I was about to 
give up in despair, when I thought I would try 
soldering; and, to my surprise, it not only 
stood while I completed the small job I was 
then doing, but is in use still, and will stand 
all the force such a file needs to have applied 
to it in ordinary use. I used ordinary solder, 
Baker's soldering fluid, and a Bunsen burner. 
The temper is injured only at the very joint. 
Of course I was careful not to heat it more than 
requisite to melt the solder.*' 
[Baker's soldering fluid is, we presume, a 
solution of zinc in hydrochloric acid. — Ed.] 
To Crystallize Paper and Glass. 
The following process is recommended by 
Professor Bottger: Mix a very concentrated 
cold solution of salt with dextrine, and by 
means of a broad, soft brush, lay the thinnest 
possible coating of the fluid on the surface to 
be covered. After drying, the surface has a 
beautiful, bright mother-of-pearl appearance. 
To make the coating adhere to glass, it is only 
necessary to varnish it with an alcoholic solu- 
tion of shellac. The following salts give the 
finest crystallizations: Sulphate of magnesia, 
acetate of soda and sulphate of tin. Colored 
glass thus prepared gives a good efiPect by 
transmitted light. 
BOOK NOTICES. 
physical Teclinics; or Practical Instructions 
for Making Experiments in Physics, and the 
Construction ot Physical Apparatus with the 
most Limited Means. By Dr. J. Frick. Trans- 
lated by John D. Easter, Ph. D. Seven hundred 
and ninety-seven illustrations. Price $3.00. 
Philadelphia: J. B, Lippmcott & Co. 
This book is to the experimenter in Natural 
Philosophy what Faraday's " Chemical Manipula- 
tion" was to the chemist. It contains not only 
minute directions for performing experiments suc- 
cessfully, but very clear instructions for making 
apparatus and using the ordinary tools. In many 
respects it is the best work on mechanical manipu- 
lation now before the public, and so far as amateurs 
are concerned, this is certainly true. All the vari- 
ous arts, such as glass-blowing, screw-cutting, sol- 
dering, brazing, working with files, planes, etc., 
are very fully treated. Our readers, old and young, 
will find it a mine of useful information. 
The Amateur's Handbook of Practical In- 
formation for the Workshop and the Labora- 
tory: Containing clear and full Directions for 
Bronzing, Lacquering, Polishing Metal. Staining 
and PoUshing Wood, Soldering, Brazing, Work- 
ing Steel, Tempering Tools, Case-Hardening, 
Cutting and Working Glass, Varnishing, Silver- 
ing, Gilding, Preparing Skins, Waterproofing, 
Making Alloys, Fasible Metals, Cements, Glues, 
etc., etc. Price 10 cents. New York: Industrial 
Publication Company. 1878. 
This is not a mere book of recipes clipped from 
old journals and encyclopcediaa, but a carefully 
compiled book of instructions for performing those 
little technical operations which are so frequently 
required in every-day life, and in the workshop of 
the amateur. In most of these operations the 
recipe is but half the battle; when we come to put 
it in operation we are apt to fail from ignorance of 
some general principle, or from inattention to some 
important though apparently trifling detail. In 
the book before us this defect is avoided, and min- 
ute practical directions are given, so that any one 
may be able to put the recipes in practice. This is 
specially apparent under such headings as 
glass-cutting, lacquering, steel working, brazing 
and soldering, silvering, staining woods, water- 
proofing, etc. 
To Fix Pencil Marks so tbey will Not Rntv 
Ont.—Take well skimmed milk and dilute with an 
equal bulk of water. Wash the pencil marks 
(whether writing or drawing) with this liquid, 
using a soft camel-hair flat brush, and avoiding 
all rubbing. Place upon a flat board to dry. 
Carrying Water in a Sieve._The following 
simple experiment will perhaps interest some of 
our readers: Take a tumbler and tie over its mouth 
a piece of bobbinet or other open fabric; immerse 
it in water, and when partly or entirely full, invert 
it, and Uft it carefully out of the water bottom up- 
wards. The water will not run out, but will remain 
suspended in the tumbler. 
Packing Glass Ware—Every one has this* 
duty to perform occasionally, and it is well to know 
how it should be done. The safety of glass articles, 
packed together in a box does not depend so much 
upon the quantity of packing material used, as 
upon the fact that no two pieces of glass come into 
actual contact. In packing plates, a single straw 
placed between two of them will prevent them^ 
from breaking each other. In packing bottles in 
a case, such as the collecting case of the micro- 
scopist, and the test case of the chemist, rubber 
rings shpped over each, will be found the best and 
handiest packing material. They have this great 
advantage that they do not give rise to dust. 
