290 THE YOUNG 
turpentine has been mixed, if placed in the nests, 
is a good preventive against vermin.— Sam R. 
107 —The Camera Lucida is simply a four-sided 
bar of glass, with two of its faces at right angles 
to each other, and the other two at an angle of 
135°. The glass is held with the right angle up- 
wards, and the eyes being dii-ected down upon 
the surface, see. reflected from the sloping sides, 
the object down the tube of the microscope, or 
whatever the instrument may be. A Camera Ob- 
scura is a rectangular box with a lens, whose 
focal length is equal to the length and depth of 
the box. This has a reflector fixed at half a right 
angle behind it, and this throws the image of the 
object toAvards which the lens is directed on to a 
piece of ground glass fitted into the top of the 
box.— Z. 
Queries. 
108. — I want to do some gilding of letters and 
ornamental work on glass, and if some fellow- 
reader who is " up to the business " will give me 
a little information on the subject, he, or she, 
will confer a favor on an Amateub. 
109. — How are sea-shells bleached and made to 
look so clean ?— Sadie. 
110. — Please answer the following question 
through the Young Scientist: If a large dwell- 
ing, containing nineteen rooms, besides kitchen 
appointments, and is standing apart from any 
other building, and is surrounded by trees and 
shrubbery, is it not a villa ?— Dispute. 
111. — A few hints from any com{)etent reader on 
the construction of an ^olian Harp will be thank- 
fully gobbled up by a young Wood-Spoiler. 
112. — Will some one kindly explain to a dull 
boy what is meant hy specific gravity, and oblige 
an old subscriber.— Jumbo. 
113. — Is it known wh(in the manufacture of glass 
first began ?— Antiquarian. 
114. — I would be pleiised if some reader of the 
Young Scientist would inform me who wrote 
the following lines:— 
" Yes, this is Love, the steadfast and the true, 
Th' immortal glory which hath never set; 
The best, the brightest boon the heart e'er knew ; 
Of aU life's sweets the very sweetest yet ! 
O, who can but recall the eve they met 
To breathe, in some green walk, tlieir first young vow, 
While summer flowers with moonlight dews were wet. 
And winds sigh'd soft around the moimtain's brow. 
And all was rapture then which is but memory now." 
—Katie B. 
Retail Prices. 
IMPORTED CAGE BIRDS. 
Canaries, Belgian, per pair $6.oo to 15.00 
" per pair 6.001015.00 
" Germa7t, Hartz hits., each 2.50 to 10.00 
Gold Finches, each 1.50 
Gold Fim h (mules), each 2. 50 to 5.00 
Bull Finches, not trained, each 2.50 
Bull Finches, trained to sing two tunes, each. 10.00 to 40.00 
African Finches, per pair 2.5010 5.00 
Chaffinches eacli 1.50 
Talking Mino or Mina '. . .10 00 to 25.00 
Linnets, each 1.50 to 2.00 
Linnets (mules), each 2.50 to 5.00 
Green Linnets, each 1.50 
Java Sparrow = (l)liie), eacn 1.50 
Java Sparrows (white), per pair 6.00 to 8.00 
English Sparrows, per pair i.oo 
Siskins, each. i.oo 
Gray Cardmal, each 4.00 to 5.00 
SCIENTIST. 
Nightingales, each 8.00 to aj.©* 
Japanese Nightingales, each 5.00 to 10.00- 
Thrushcs, each 5.00 to 7.00 
Skylaiks, eacli 5.00 
Troopials, eacli 7.00 to 12.00 
European blackbirds, each 5 00 to 7.00- 
Biack-caps, each 4.00 
Starlings, e..ch 4.00 to 6.00 
PARROTS. 
Gray Parrot 10.00 to 15,00 
Single Yellow-Head Parrot 8.00 to 12.00 
Double Yellow-Head Parrot 10.00 to :5 00 
West [ndian " 4.00 to 5.00 
Cockatoo (white) 18.00 
Australian Shell Paraquets, per pair. 6.00 
" Love Birds," African Paraquet^;, per pair. . . 6.00 
West Indian Paraquets, per pair 3.00 to 5.00 
All birds that are accomplished singers or talkers bring 
high and "fancy" prices. Parrots are rated by the num- 
ber of words, sentences, and tunes they have learned. 
AMERICAN CAGE BIRDS. 
Canaries, each 2.50 
Mocking Birds, females, each, i 00 
" " singers 12.00 to 25.00- 
Robins 2.50 to 5.00 
Blue Birds ("Blue Robins") each 1.50 
Indigo Birds, each i.oo 
Nonpariel. each. . 1.5010 2.00 
Virginia Cardinal, each 3. 50 to 3.00 
Bobolinks, each ^ „ 1.50 to 2.00 
Yellow Birds, each 1.50 to 2.00 
J^'ices Paid hy Dealers. 
Robins, per hundred 12.00 
Blue Robins (i^lue-Birds), per pair 0.35 
Indigo Birds, each 0.50 
Bobolinks, per dozen 3.00 
Yellow-Birds, perhundred 12.00 
Orioles, per hundred 25.001035.0® 
Virginia Cardinals (Red-Birds), each 0.75 to i.oo 
Nonpareils, each 0.75 
Blue-Jays, each .„ 0.35 
Scarlet Tanagers, each 1, oo- 
Red-Wniged Starlings, or Black-Birds, each.. 0.25 
Woodpeckers (" High-Holers"), each.._ 1.00 
Partridges, each " 1.50 
Cranes, each (according to variety) 10.00 to 20.00 
Wood-Ducks, per pair 2.50 
Wild Bronze Turkeys (one cock, two hens) .... 10.00 to 15.00 
FANCY POULTRY. 
Guinea or Pea-Hens 12.00 
Pheasants, English, per pair 20.00 
" Golden, " 35-oo 
" Si/ve^, " 30.00 
Pea-Cocks, per pair 20.00 to 75.00 
Bronze Wild Turkeys 15 00 to 20.00 
White Turkeys 10.00 to 15 00 
Bantams, trio. 3.00 to 10.00 
Rmg-Doves, per pair 1.50 
Pigeons, common, per pair 0.75 
" a// white, co7nmon, per pair 1.00 
BIRD FANCIERS' MATERIALS. 
Breeding Cages (double) 1.50 to 4.00 
Trap Cages o. 75 
Wire " painted 0.5010 4.00 
Wood and Wire Cages 1.50 to 4.00 
Prepared Bird Food, per quart 0.30 
Bird Clravel, per quart , 0.05 
German Rape Seed, per quart 0.20 
Canary Seed, per quart 0.20 
McAllister's Mockmg-Bird Food, ilb. jar 0.35 
" Canarv-Rird Food, ilb. box. 0.20 
" Mixed I«iid Seed, ilb. box o.io 
" Extra Silver Bird Gravel, qt. box. o.io 
McAllister's Prepared Fish Food, per bftx,... 0.10 
" Song Restorer, for birds, per hot. 0.25 
McAllister's l^ird-Lice Destroyer, in patent 
bellows box , 0.25 
McAllister's Bird Lime, per box 0.25 
Cuttle- Fish Bone, each 0.05 
Meal-Worms, per hundred 0.40 
Nest Boxes, wire and tin, 0.10 to 0,15 
Nest Materia], per bunch 0.10 
