152 
THE YOUNG SCIENTIST. 
lose none of his interest or influence ; the 
Young Scientist will still be what it always 
has been, the representative of the Ama- 
teur Scientist and Mechanic. But with 
relief from the burden of minute detail 
comes greater opportunity to accom- 
plish more important things, and main- 
tain more thoroughly the more important 
departments. 
With the January number, Mr. Fred. T. 
Hodgson, whose name is familiar to 
every reader of the Young Scientist, will 
join us in our editorial work. If you de- 
sire to see the results, just send on your 
subscription for 1883, or send by postal 
card a request for the January number. 
Practical ^ints. 
~ To' Bend a Pipe.— Fill it with melted resin. 
When the resin hardens bend the pipe, and it 
will retain its round form. Eemove the resin by 
heating. 
I [Iiig-hting: Fires.— Many housekeepers have a^ 
some time realized the diflficulty of lighting a grate 
lire in a still, damp morning, when the chimney 
Avill not draw, and vigorous blowing proves in- 
eflfectual. Science explains the trouble as "caused 
by the difficulty encountered in overcoming the 
inertia of the long column of air in the pipe or 
chimney by the small column of air that can be 
forced up through the interstices of wood and 
coal, at the bottom of which the fire is kindled." 
This may be remedied by first lighting a few bits 
of shaving or paper placed upon the top ; thus, 
by the heated air's forcing itself into the chimney 
and establishing there an upward current, the 
room is kept free from the gas or smoke which is 
so apt to fill it, and the fire can then be lighted 
from below with good success. 
Blacking- Brass.— A correspondent of the 
English Mechanic says : I have tried all the various 
recipes recommended— nitrate of silver, platinum 
bichloride, etc.— but never found any work so 
satisfactorily and cheaply done as by the reduc- 
tion of nitrate of copper to the oxide. I find the 
best way of using is to apply the solution to the 
brass to be blacked with a camel-hair brush, pre- 
viously slightly heating the metal ; then to raise 
the heat until the requisite color is produced ; 
finishing by rubbing with a soft rag, and either 
oiling or lacquering. I can confidently recom- 
mend this as the very best method of producing 
that good black seen in first-class optical goods, 
observing that the process will not do for soft- 
soldered articles, as the heat necessary to produce 
the black is greater than the melting point of soft 
solder. 
EXCHANGES. 
Only those who are yearly subscribers, and whose names 
are entered on our books have the privilege of inserting ex- 
changes. 
Exchanges must be on separate slips of paper or postal 
cards. If mixed with business matter in letters or cards they 
are filed away and never reach the printer. 
Exchanges must not exceed thirty words. 
Buying and selling belong to the advertising department. 
We reserve the right to omit the exchange column, when 
we have not room for it, and the amount of space at our dis- 
posal will regulate the number of insertions given to each 
exchange, the preference being always given to those v/ho' 
have not previously used our columns. 
I have a large assortment of foreign stamps to exchange,, 
also Confederate money. Collectors send sheet and I will 
return it with mine. Box No. 2, Coeymans, N. Y. 
Electric bell engine, cost $15 ; pair of analytical scales, 
cost $10 ; pair of Bell Telephones to exchange for a printing 
press, watch or offers. Geo. N. Bigelow, Box 754, Palmyra, 
N. Y. 
To exchange for ofTers first four (fifth when completed) 
bound volumes of Young Scientist. J. N. Brooks, P.O. 
1468, N. Y. City. 
Any person wishing to trade bird's eggs may apply to 
me and I will send them my list of bird's eggs. I have only 
a few at present, but am receiving a number every month. 
A. G. G., Box 26, Summit, New Jersey. 
Minerals of Idaho for Standard Works on the Horse — 
Wallace's Registers and turf journals. Wanted, also other 
useful books, bound and in good condition. Many varieties 
named in my list. J. P. Clough, Junction Lemhi Co., 
Idaho. 
Wanted engraver's tools with book of instructions, for a 
Victor Press, with cabinet, 2 type cases, type, ink roller and 
furniture complete ; perfectly new. L. Warren, 72 Cumber- , 
land St., Brooklyn, N. Y. 
A Fletcher Foot-Blower, cost $5, as good as new; will 
exchange for a Cushman, 2 in. or up scroll chuck, or other 
make; will give a satisfactory trade on the difference in 
price, if any. Louis Lutz, St. Clair Street, Toledo, O. 
I have a lot of " Galaxy " (magazines) which I would 
like to exchange for an air rifle in good condition, a collec- 
tion of birds' eggs, or offers. W. B. Greenleaf, 480 
La Salle Ave., Chicago, 111. 
I have a Mechanical Telegraph with book of instructions,, 
books, etc., which I wish to exchange for good microscopical 
objects, mounted on 3x1 slips. Address, with list, J. H. 
Frey, Millersl urg, Ohio. 
To exchange, " How to Use Microscope," Wells* "Na- 
tural Philosophy," and many other books, chemical appa- 
ratus, etc., for good photographic camera, and lenses. W. 
H. Weed, 254 Putnam Ave., Brooklyn, N. Y. 
Wanted "Quimby's New Bee Keeping," for "Our 
Own Birds of the United States," by W. S. Baily ; new. 
Joseph Anthony, Jr., Colota, Whiteside Co., 111. 
Wanted a good book in anatomy, in exchange for a book 
on chemistry, or for story books. A. G. G., Box ■2(>^ 
Summit. New Jersey. 
A German-silver trimmed, patent lined, cocoa flute, cost 
$4, in good order, for good spy-glass, photo-material, or 
offers. Ewing McLean, Greencastle, Ind. 
I have some fossil shells from the west bank of the 
Mississippi, to exchange for Indian relics. A. W. S., 187 
E. 71st St., N. Y. 
I have a magic lantern, Ruby pattern, nearly new, and 
5 views; also "Our First Century," bound in leather, cost 
$7; state what is wanted in exchange. I. N. Spenceh, 
Box. 217, So. Manchester, Conn. 
First-class telegraph instrument and attachments, and 
"Wood's Botany," for bound volumes of periodicals, books, 
or offers. H. P. Albert, Anderson, Iowa. 
Wanted a book on treatment and care of canary, also 
breeding of same; will give in exchange book name(f ^ 
"Market Garden, Flower Garden and Bees," or \ 
"Scientific Americans" or "Seaside Libraries;" wfg~ 
also old books. M. J. Mulvihill, Norwalk, Conn. ^ 
