100 THE YOUNG 
SCIENTIST. 
Drilling Glass. | 
One of our exchanges gives the following 
directions for making holes in glass :— 
Stick a piece of stiff clay or putty on the part 
■wiaere you wish to make the hole. Make a 
hole in the putty the size you want the hole in 
the glass, reaching to the glass, of course. Into 
this hole pour a little molten lead, when, unless 
it is very thick glass, the piece will immediately 
drop out. 
We would advise our readers not to try this on 
any article that they value. In nine cases out 
of ten instead of making a clean hole, the mol- 
ten lead will break the glass all to pieces. A 
clean round hole may sometimes be made in 
a plate of glass by shooting a bullet through 
it. In most cases however the bullet shatters 
the glass. 
To Take Bruises out of Furniture. 
Wet the part with warm water; double a 
piece of brown paper five or six times, soak it 
in warm water, and lay it on the place ; apply 
on that a warm, but not hot, flat-iron, till the 
moisture is evaporated. If the bruise be not 
gone, repeat the process. After two or three 
applications, the dent or bruise will be raised to 
the surface. If the bruise be small, merely soak 
it with warm water, and hold a red-hot iron 
near the surface, keeping the surface continu- 
ally wet— the bruise will soon disappear. 
The Egyptian Cubit. 
In noticing the labors of the International 
Bureau of Weights and Measures, Abbe Moigno 
regrets the choice, as the unit of measure, of the 
ten-millionth of a meridional quadrant, " a unit 
fatally indeterminate," since the meridians vary 
in length. He suggests, as a better standard, 
the cubit of the Great Pyramid, which repre- 
sents the ten-millionth of the earth's polar axis. 
Sir John Herschel made the same proposal, 
nearly thirty years ago, and it is somewhat re- 
markable that his views should be now advo- 
cated by Les Mondes, the leading Trench scien- 
tific journal. 
EXCHANGES. 
Only those who are yearly subscribers, and whose names 
are entered on our books have the privilege of inserting ex- 
changes. 
Exchangesmust be on separate slips of paper or postal 
cards If mixed with business letters or cards they cannot 
be used. 
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. 
Wanted, " Butler's Family Aquarium ; " will give 
in exchangre two books, entitled " Laughing G-as " 
and " De Walden's Ball-room Companion." E. 
B. Brown, Box 25, Covington, Ind. 
Wanted, a good microscope in exchange for a 
scroll saw: instrument must be in good order, 
and magnifying power of from 200 to 300, or 400 
diameters. H. E. Rhodes, Brighton, Iowa. 
A patent spectograph, cost when new $1.25 ; rare 
minerals, birds' eggs, and postage stamps, to ex- 
change for minerals, foreign coins, Indian relics, 
or offers. Frank F. Fletcher, St. Johnsbury, Ver- 
mont. 
Eggs, of the English sparrow, for good speci- 
mens of other birds' eggs ; botanical specimens 
mounted and unmounted to exchange ; lists ex- 
changed. C. R. Hexamer, New Castle, Westchester 
Co., N. Y. 
What is offered for one of the Climax extension 
step ladders? H, E. Phelps, Manhall, Michigan. 
To exchange, a $3 microscope for some old 
issues of Canada postage stamps. Wallace Ross, 
Lock Box 97, Rutland, Vt. 
Wanted to exchange, Colorado minerals, such 
as jasper, smoky quartz, silicified wood, etc., for 
good specimen fossils, or perfect crystals of min- 
erals of other localities. H. F. Wegener. Denver, 
Colorado. 
One Natural Philosophy, one Bryant & Strat- 
ton's Counting-house Book, and two long bows, 
with arrows, to exchange for cabinet specimens or 
curiosities. W. D. Wright, Lock Box 17, Bremen. 
Indiana. 
Wanted, coins, minerals, and type ; send lists 
of what you have and what is wanted in exchange. 
A. Campbell, Derrick City, McKean Co., Pa. 
An Excelsior Printing Press, with equipments, 
comparatively new. cost over $47, for double barrel 
breech-loading shot gun, with reloading tools and 
shells. William A. Hervey, Box 134, Taunton, 
Mass. 
To exchange, 400 stamps, all different, in a stamp 
album, for a small printing press with type, etc. 
Arthur D. McGerald, 106 Bird Ave., Buffalo, New 
York. 
To exchange, $5 pair of telephones for mounted 
microscopic specimens, good objective, lathe 
chuck, watch, type and cases, or offers ; describe 
offers. Wm. R. Brooks, Phelps, N. Y. 
What offers for Roger Scroll Saw, 55 large pat- 
terns. J. Brower. 3,150 Frankford Road, Phila- 
delphia, Pa. 
Scroll sawing outfit, $6; microscope, $3; pocket 
telescope, $l ; Gaskel's Compendium, $1 ; Williams' 
Complete Painters' Guide, $2. What offers for all 
or part; printing outfit preferred. F. W. McNair, 
Box 46, Fennimore, Wis. 
$7 worth of books or papers, to exchange for a 
Household microscope or offers. Jonas D. Rice, 
221 Academy St., Mercer Co., N. J. 
Idaho cabinet minerals, books, revolver, stencil 
outfit, an electrizer, for well-bound books of 
travel, biography, history, science, masonry and 
others of an instructive nature. J. P. Clough, 
Junction P. O., Lemhi Co., Idaho, 
Dumb bells of all sizes, to exchange for most 
any thing ; send for circular containing weights 
of them to J. P. Donohue, Box 7, Davenport, Iowa. 
Wanted, scientific books and papers, micro- 
scope, drawing instruments, telephone, stamps 
and coins, in exchange for scroll iaw, type, cards, 
revolver, shot gun, magazines, scientific books, 
or almost anything. W. L, Goodsell, Bath, N. Y. 
A pair of New York Club skates, worth $3.50, 
also coins, minerals and postage stamps, for 
books or offers ; correspondence invited. E. F. 
Greene, P. O. Box 889, Bath, Steuben Co., N. Y. 
A nice marine oil painting, ready framed, worth 
$5.00 ; state what is offered in exchange. C, Ham- 
mond, Artist, P. O. Box 47, Chatham, Barnstable 
Co., Mass. 
Photographic camera, one portrait and one land- 
scape tube, with chemicals complete, in exchange 
for medical books. J. Frederick Herbert, 1,324 
Poplar St., Philadelphia, Penn. 
Trump's and Russel's scroll patterns, worth 
$10; for large lenses preferred. H. J. Peters, 
Rogersville, Ohio. 
