THE TOUNG SCIENTIST. 
31 
was, considering the period and the obstacles, 
considerable activity in this branch of manufac- 
tures, which has been increasing ever since. 
\XMimi 
— When color on a fabric has been accidentally 
or otherwise destroyed by acid, ammonia is ap- 
plied to neutralize the same, after which an ap- 
plication of chloroform will, in many cases, re- 
store the original color. The application of am- 
monia is common, but that of chloroform is but 
little known. 
Oil Polish for Dining: Tables.— One quart of 
linseed oil to be simmered (not boiled) for ten 
minutes and strained through flannel ; then add 
an eighteenth part of spirits of turpentine ; to be 
applied daily with a soft linen rag, and wiped off 
lightly. The only polish that will resist hot 
dishes. 
Bronzing- Liquid. — Ten parts of aniline red 
iind flvcLparts of aniline purple are dissolved in 
100 parts of 95 per cent alcohol, on the water-bath, 
and the solution, after the addition of five parts 
of benzoic acid, boiled (for 5-io minutes) unril it 
has changed its greenisn 2olor to light bronze- 
brown. Applied with a brush upon leather, metal 
or wood, the liquid produces a magnificent oronze 
coating, 
Grlueing".— French cabinet-makers useagluc- 
pot with an inside pan made of giazed earthen- 
ware and divided radially into three divisions, in 
one of which is [ kept strong glue, in another 
weaker, and in the third water only, with a brush 
or piece of sponge, for cleaning off superfluous 
glue from the work. Chalking the joints in glue- 
ing end-wood is not to be recommended ; a better 
plan is to size the end-grain with thin glue first, 
and then make a smooth face before glueing per- 
manently. 
Hardening Steel.— For hardening thin steel 
articles Dr. Hartman recommends: qts. of 
train oil, 2 lbs. of beef tallow, }i lb. of beeswax, 
and 1 lb, of resin. The exact amount of resin, 
however, is a matter of experiment, always bear- 
ing in mind that the greater the proportion of 
resin the higher the temper. Another mixture 
recommended on the same authority, is 95 qts. of 
spermaceti oil, 20 lbs. of tallow, 4.}z qts. of neats- 
foot oil. 1 lb. of pitch, and 3 lbs. of resin. The 
pitch and resin are melted, the other ingredients 
added, and the Avhole heated until it will ignite if 
a blaze is brought in contact with it, when it is 
covered and allowed to cool. 
— In the Polytechnisches Notizblatt, M. Tilhet's 
method of copying drawings in any color that 
may be required or desired is thus described: 
"The paper on which the copy is to appear is 
first dipped in a bath consisting of 30 parts of 
wrhite soap, 30 parts of alum, 40 parts of good 
glue, 10 parts of albumen, 2 parts of glacial acetic 
acid, 10 parts of alcohol of 60°. and 500 parts of 
water. It is afterwards put into a second bath, 
which contains 50 parts of burnt umber ground 
in alcohol, 20 parts of lampblack, 10 parts of good 
glue, and 10 parts of bichromate of potash in 
500 parts of water. They are now sensitive to 
light, and must therefore be preserved in the 
dark. In preparing paper to make the positivt; 
print, another bath is made just like the first one, 
except that lampblack is substituted for the burnt 
umber. To obtain colored positives, the black is 
replaced by some red, blue, or other pigment. In 
making the copy, the drawing to be copied is 
put into a photographic printing-frame, and the 
negative paper laid on it, and then exposed in 
the usual manner. In clear weather an illumina- 
tion of two minutes will suffice. After the ex- 
posure, the negative is put in water to develop 
it, and the drawing will appear in white on a dark 
ground; in other words, it is a negative or re- 
versed picture. The paper is then dried, and a 
positive made from it by placing it on the glass 
of a printing-frame, and laying the positive 
paper upon it, and exposing as before. After 
placing the frame in the sun for two minutes, 
the positive is taken out and put in water. The 
black dissolves off without the necessity of mov- 
ing it backwards and forwards," 
The Builder's Gruide and Estimator's Price 
Sook. Being a compilation of Current Prices 
of Lumljer, Hardware, Glass, Plumbers' Sup- 
plies, Paints, Slates, Stones, Limes, Cements, 
Bricks, Tin, and otner Building Materials ; also. 
Prices of Labor, and Cost ol Performing the 
Several Kinds of Work required in Building; 
together with Prices of Doors, Frames, Sashes, 
Stairs, Mouldings, Newels, and other Machine 
Work. To which is appended a large number 
of Building Rules, Data, Tables and Useful 
Memoranda, with a Glossary of Architectural 
and Building Terms, By Fred, T. Hodgson, 
Editor of "The Builder and Wood- Worker" ; 
Author of " The Carpenter's Steel Square, and 
its Uses," Etc., Etc, 1vol., ]2mo., cloth, gilt. 
Price, Two Dollars. New York: The Industrial 
Publication Company. 
The scope and character of this work are so 
fully set forth in the title that nothing need be said 
as to its contents ; they speak for themselves, and 
at once commen(J the volume to those who are 
seeking for the information which it contains. 
But as regards the execution of the book a Avord 
or two may not be out of place. 
The value of a volume of this kind will depen<l 
upon three things: First, the need which exists 
for such a book ; secondly, the good judgment 
that is exercised in selecting the information 
that is given; and thirdly, the fidelity and care 
with which the work is done. 
As regards the need for such a book there can 
be no question. Every architect, contractor, 
builder, and even every country carpenter, feels 
the need of just such a book as that before us. 
Several attempts have been made to supply the 
