32 
THE YOUNG SCIENTIST. 
sun shone at Washington would reflect to Boston. 
The labor of measuring the brightness of all the 
visible stars was begun two years ago. It has 
since gone on at the rate of about 40,000 a year, 
and will be completed next fall. 
QUESTIONS AND ANSWERS. 
Burning Ieon Wiee with a Batteey.— Can 
anyone tell me how to heat or burn iron wire, 
and other experiments with the tin can battery 
described in vol. l. H. A. K. 
Ans.—in making this experiment three points 
require care : l. fSee that the battery is in vigor- 
ous action. 2. When only one cell is used, see 
that the wires attached to the poles are short and 
stout, and well soldered to the copper and zinc, 
y. See that the iron wire is Short and very fine. 
The conductors or wires should not be more than 
twelve inches long, the solutions must be strong 
and warm. The finest iron wire— not thicker 
than a human hair— nust be used. Such wire may 
be procured from most dealers in wire, or any 
watch maker can give you a bit of the balance - 
spring of a watch (not the main-spring). You 
should have no difficulty in burning a bit of fine 
wire with a single quart cell. Wollaston used to 
astonish his friends by igniting a piece of fine 
platinum wire by means of a battery made ou4^f 
a lady's silver thimble. W 
How can brass drawing instruments be made so 
they will not tarnish and have that bad smell ? 
An answer to the above will oblige a 
Beass Monkey. 
^w.s.— We find that a correspondent of Carpentry 
and Building asks a similar question in regard to 
bird cages, and is answered as follows: "After 
thoroughly cleaning and removing the last traces 
of grease by the use of potash and water, the cage 
or other brasswork must be carefully rinsed with 
water and dried, but in doing it care must be 
taken not to handle any portion with the bare 
hand, nor anything else that is greasy. The pre- 
servative varnish may be shellac much» diluted 
with alcohol, or it may be hard oil finish. We 
have tried the latter and found it to work very 
well. In either case the brass should be made 
pretty warm, and the varnish or shellac put on 
with a brush in as thin a coat as possible. In 
some places the stores sell the shellac varnish 
under the name of ' lacquer.' It is considerably 
thinner than the ordinary bronze shellac, and 
rather a nicer article. The proportion of shellac 
to alcohol is about two ounces of shellac to nine 
ounces of alcohol. Sometimes gamboge is used 
for a coloring matter to make the varnish more 
yellow, and sometimes dragon's blood." We fear, 
however, that any lacquer or varnish would soon 
disappear from articles which are handled as 
much as mathematical instruments. The best 
method is to have them nickel-plated, or if you 
are about to purchase a set, get them of German 
silver. 
HORSFORD'S ACID PHOSPHATE. 
Speaking of this preparation, Dr. C, P. Bussell, 
of Utica, N. Y,, says: "I have used Horsford's 
Acid Phosphate in a number of cases of nervous 
debility with good results. Partial insomnia was 
a prominent symptom in some. It invariably 
stimulated appetite and relieved the insomnia. I 
think it a meritorious agent in these cases." 
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 who 
have not previously used our columns. 
Model card press, chase 3 x s J^^, with 4 fonts type, cases, 
etc., for good foot lathe. Mills Day, 2 Farmington Av., 
Hartford, Ct. 
French microscope, inclines to any angle, delicate fine 
motion, neat upright case, cost $17.50, for scientific books; 
send list to W. Fiiz, P.O. Box 2852, New York. 
Wanted, Quinby's New Bee Keeping, for Our Own Birds 
of the United States, by W. S. Baily ; new. Joseph 
Anthony, Jr., Coleta, Whiteside Co., Illinois. 
Printing type, small pica ; large and .small capitals, and 
small letters ; 60 to 65 lbs., including two large cases; also 
gothic nonpariel, for trade. J. Siler, 1242 Broadway, St. 
Louis, Mo. 
One years' copy of Aldine, cost $5.50, and German 
accordion, with instructions how to use it, cost $5.00, for 
offers. Chas. Dempwolf, 86 Benson St., Paterson, N. J. 
A Novelty printing press, with type, prints a form 5x7 
in'^hes, cost $40.00, for a microscope, photographic appa- 
ratus, or offers. T. W. Patterson, Warsaw, N. Y. 
$80 worth of (nearly new) printing material, minerals, 
fossils, Aboriginal reHcs, etc., for scientific books, good 
American watch, and offers. F. M. Farrell, Cobden, Union 
Co., Ills. 
Rocks, minerals, fossils and fresh water shells for micro- 
scope stand, $20 to $75, also for objectives, turning lathe, 
type, and tools. D. L). Babcock, South Dansville, N. Y. 
Mechanical Electricity, Medical Chemistry, by Robert 
Hare ; Fruits and Farinacea, by Trail ; Complete Herbalist, 
by O. P. Brown ; for mounted objects for the microscope or 
offers. J. B. Playter, Bristow, Buder Co., Iowa. 
Violin (cost $10) and 5-shot 32-cal. revolver (cost $4), for 
photo-camera lens and tube, watch, parlor rifle, extra 
well-bred canary birds, or offers. C. Maides, St. Louis, Mo. 
To exchange for a wood-turning lathe or offers, a Young 
America Self-inking Printing Press, with type and outfit 
complete ; chase 3x5 inches. Embury McLean, 318 Bloom- 
field St., Hoboken, N. J. 
What offers for " Our First Century," cost $7.00, bound 
in sheep, over 400 illustrations, 1,000 pages; also small 
Ruby Magic Lantern, cost $1.50. Box 217, So. Manchester, 
Conn. 
Magic lantern, in good order, condensing lens, 2^ in. 
diameter, 8 slides. For small photographic camera or offers. 
H. A. Giddings, 4 Union Place, Classon Ave., Brooklyn. 
Printing press, type, etc., worth $13, for offers. E. G. 
Vogeley, loio Bradford St., Pittsburgh, Pa. 
Fifty canary birds, with and without crests ; fancy 
poultry, conch shells, strombus alatus. For small prindng 
press, books on natural history, or offers. Frank Lattin, 
Gaines, N. Y. _ 
A good plain 7 shot revolver, 22 calibre, for a Students' 
inch or half-inch objective. Frank F. Colwell, Urbana, 
Ohio. 
Wanted, Printing press and type, in good order, chase 
6 x ID, or larger ; will give hardware, tools, scroll saw, or 
designs. Chas. E. Little, 59 Fulton St., New York. 
Photo outfit, tools, chemicals and apparatus, etc., etc.; 
wanted scientific books, apparatus, etc.; send lists. A. B. 
Campbell, Box 59, South Dayton, Catt. Co., N. Y. 
Stuffed birds, insects or job printing (cards, labels, etc.) 
for mounted objects for the microscope. James P. Melzer, 
Milford, N. H. _ 
A nng stand, filtering stand, calcium light jet and a gas 
holder, holding one cubic foot, for a phonograph. D. P. 
Smith, 59 Park Place, New York. 
