1877.] 
AMERICAN AGRIGULTQRIST. 
453 
so complete and desirable, has hUlierto been offered to 
the ge?ieral public at so low a price as S3>50. llVith 
the imprOTements in mode ol manirfacture, and 
the great number contracted for, this instru- 
ment will be supplied at retail for only gl.50. 
KUT to every actual subscriber 
to the American. Agricultiirist for 
1878, one of these Microscopes -trill 
be supplied complete for 4,0 cents 
abore tbe subscripti<^n price, and 
to tbe cliib snbscribers at only 33 
to 35 cents aboT-e the club subscrip- 
tion rates tTben taken at tlie office 
or its delivery provided for. The 
Publishers will pay tor the addi- 
tional cost of manufacture — a large 
sunt in the ag-gpregate. 
HEBE ABE THE TEBMS : 
{The Ameriean Agriculturist will be sent post-paid 
from receipt of subscription to the end of ISTS. The 
Microscopes will be deliTered as provided below.) 
One Subacrlpion and One Microscope f2.0O 
2 Subacriptions and 2 Microscopes ig3.80 ($1.90each.) 
3 Subscriptions and 3 Microscopes ?5."^ (J1.75 cacb.) 
4 Subscriptions and 4 Microscopes ?6.G0 .$l.G3cacb.) 
5 toQ Subscribers and 1 Microscope each f l.fJO each. 
10 to 19 Subscribers anda Microscope cac'.i ?1.55 each. 
20 Subscribers anda Microscope each J1.44 eac^. 
Or, In clubs of 20 and upwards, ?1.10 for each subscrip- 
tion, and S3J^c. for each Microscope, (that is. fl extra for 
every three Microscopes, in all clubs of twenty or more.) 
Ij^f It win thus be Been that the $1.50 Micro- 
scope (really worth at least $'.i.50, as compared 
with anything ever before ofEered) can be obtained 
by any regular subscriber to the Am. Agricniturist 
for 187S, and by such only, for the small extra cost 
of only 33 to 40 cents, as above. This is surely get- 
tlDR double value for one's money, and more. 
Delivery of tlie Micro§copes. 
I. Any subscriber for 1878, will receive the 
Microscope on calling or sending for it at the Office, 
245 Broadway, without expense, save the small 
payment of 33 to 40 cents above sta,ted, which is 
only a part of the actual cost of manufacture alone. 
II. 'WTienever there is a club of subscribers at 
any place, one of their number can be appointed 
to receive the Microscopes for all, and have them 
come by express, making the cost of cariiage but 
a few cents eacli. We will pack them safely with- 
out charge, and forward them in any way directed, 
on receipt of the names for whom tliey are to be 
supplied, with the small extra sum for the Micro- 
Bcopes stated above. 
III. During the remainder of 1877, we will 
undertake to deliver them to any part of the United 
States, and Upper and Lower Canada, on reci?ipt 
of 15 cents for each Microscrope, ioT paytnrnt of 
carriage. We can only promise this for the present 
year, as we have not yet been able to make express 
and other arniugements extending beyond Decem- 
ber 31, 1877. It this can be continued, it will be 
announced hereafter. 
IV. Our subscribers in foreiirn countries, not 
named above, will need to provide for. and direct 
how the Microscope shall be forwarded to them. 
Any S'ibsi-ribcr nlrcadij on our books for 1S7S, can 
have a Microscope by remitting 40 cents, adding 
the l.ic. more if to be sent prepaid. Any one who 
has sent a club of three or more, can receive a 
Microscope for each member of his club on remit- 
ting 33J cents each, and cost of carriage to the 
address, if to be sent prepaid. 
IV. It. — The Microscope Is designed for all 
Bubscribers on our books for the Ainerican Agricul- 
turist for all of 18TS, no matter from whom received. 
We repeat, that the receipt of 40 cents from any 
subscriber for 1S7S will entitle him or her to one oC 
the Microscopes, to be taken at the office, or if to 
be sent prepaid, on receipt of 15 cts. to pay for car- 
riage, except to foreign countries, as named above. 
To all not subscribers the price will invariably 
be $1.50 each, and cost of delivery if we deUver it. 
Order of Delivering microscopes. 
They are now being made ; 3,000 will be ready 
by the time this paper reaches most of our readers, 
and the manufacture will be pushed forward rapid- 
ly, as fast as macliinery for making them can be 
constructed— probably several thousands a week. 
jg" They will be sent out in the order of receipt 
of names — first come, first serrcd. 
H 
^ 
LASS PLATES. 
The General Premium lAst not 
Aflfected by the Micro §cope Offer. 
Our General Premium List (page 481) will go on 
just the same, and all the offers hold good. Those 
having collected names for the Premiums, and 
those who do so hereafter, wUl receive the premi- 
ums just the same. To have any subscriber on 
the lists receive the Microscope, it is only necessary 
to collect and send 40 cents for each single Micro- 
scope, or SI for each three Microscopes to be sup- 
Fig. 5. Fig. 6. 
plied, and payment for their delivery, if to be sent 
prepaid by us. Simply send the cost of the Micro- 
scope and cost of delivery, if to be sent paid by 
us, in addition to the SI. GO or $1.10 in the Premium 
Table. See page 481. The Microscope will greatly 
aid all collecting Premium Clubs. Every family, 
everywhere, can well afford the full price for the 
Microscope alone, making the paper practically free. 
What Scientific Men Think of Our New 
Microscope. 
■ ♦ 
It 13, of course, unnecessary among: o^r o^^" readers to 
enforce or fortify what we say concerning tlie Micro- 
scope ; yet it may interest sonic to read whatotliers think 
of it. We sent one of tlie first complete insti-uraents to 
Prof. Rice. Professor of Geology and Natural History, 
wlio has classes in Microscopy, and largely nses a variety 
of these instruments. The Microscope next went to 
Prof. Atwater, well known to our readers by his contri- 
butions lo this Journal, and as Director of the fii-st 6uc- 
cessfnl Ag^ricultural Experiment Station in this conntr}' : 
Weslktan Univeusity. ( 
Middleton. Conn., Nov. 12, 1S77. J 
Orange Judd Compamj, Xew York; 
Genfla/ien:—2 hare /^xamintd with great ^}Iea<ure the Mi- 
crosco]}e devi^e-i by tjr>u, and mad^ under yrur auspice.f, 
and called the " Ameuicak Aoricultukal Microscope." 
It is a beautiful little in.'ifrumf'nt. Its Lenses, singly and in 
combination^ give a range of jxuver from seven to about 
iiventy-four dianwters. It can be uced both with rejected 
and with transnvf fed light. Ifyo^ican i^ell it for Two Dol- 
lars, yo'i will thereby render a real service to the comjnunity. 
I know of no Mrcroscojie so'd so low a-« $2 ivlticlt is egual. or 
nearly equal, to this in excellence. It is not a tftere toy, but 
is well adapted for use in b'^tanieal analyses, and other sci- 
entific shuiiex, which reguire the aid of a simjile form of 
MicroscofK. Tours truly. Wm. North Rice. 
7 have examined your Mtcroncope wi'h great safiff ac- 
tion, firrbscr/he fidly to whaf Prof. Rice says of it. and rcc- 
omtnend it heartily, not only to Farmers, for examining 
fertilizers, feefiing materials, and e€ed<! that are liab!e to 
adulteration, dairy products, plants, and minute animal or- 
ganisnviby whicA they are ap' to be injured, but al<o to all 
intelli'jerd people who wi'ih a Microscope, and can not qff'ot^ 
an exj'ensive one. It ix decidedly the f>est ttiingfor the price 
of $2 that I havA ever seen, and I hone it will be widely in- 
troduced and used. Tours respectfully, \V. O. Atwater. 
Some Wonders of the Microscope. 
The unaided eye lakes a very limited range of objects. 
To Bee the whole of anything a hundred feet aquare only, 
it must be so distant that its details of surface are iraper 
ceptibie. An object a hundredth part of an inch in di- 
ameter becomes a mere dot to the eye. Of the " iu- 
nnmerable elars," tlie eye sees but a thousand above 
the horizon. The great telescope at Washington reveala 
56,000,000 stars, and probably there are millions and 
billions more still undiscovered ; indeed, is there a place 
where there are no stars beyond? Each star is believed 
to bean immcuaesnu, with great planets or worlds revolv- 
ing around it Go the other way ;— there are plants and 
animals, too small for ua to see— millions, millions of bil- 
lions times more numerons than all we can see. Last 
summer, with our large microscope wc examined and 
measured animals (animalculEe) moving rapidly about in 
the tiniest drop of our aqueduct water, of which it would 
take 10,600,000,000, to fill up a single cubic inch, that is, 
eight times as many as there are people on the whole 
earth. The fine powder, called Tripoli, used for pol- 
ishing b -cause it is so fine, contains in a single inch 
the skeletons of eoniu 40. (H)0. 000. OW (forty billions .') of 
organic plants that have lived and grown. The Micro- 
scope shows that on the duckweed there are perfect 
animalculie (little animals) so small that 10,000.000,000 of 
them would no more than equal a single hemp seed in 
bulk. Many specimens of foul or ditch water contain 
animals so minute that a drop would hold myriads of 
them with ample room for them all to move about. Some 
of these seen under a powerful microscope look like 
wriggling monsters, as they are. Of course revelations 
like these are only possible by using strong compound 
Microscopes that magnify hundreds of diameters, and 
thousands of surfaces, yet it is worth while to get. when 
possible, even an instrument that will magnify 50 to 500 
areas, and thus look a little way down into the world of 
small objects every where around ns. Such an instru- 
ment is now obtainable by any one, as detailed in other 
columns of this paper. 
How a Microscope Magnifies- 
The illustration (fig 7) will explain this. X is a single 
glass lens with curved surfaces. A ray of light going from, 
thctopof thoarrowisbentdownward in passing through 
and out of the glass, and the eye sees the feather 
end of the arrow in the direction of the upper dotted 
line. On the contrary, the ray of light from the 
point of the arrow, meeting a different curve of 
the lens, is bent npward. and the eye sees this ray in the 
direction of the lower doited line. Rays from all other 
points of the arrow are similarly bent, and if the 
glass be perfectly formed, they will all meet in the 
eye, and the length of the arrow will tlms be greatly 
magnified, and its minut*^ points be clearly seen. In 
the engraving, the arrow is enlarged in length only 6 
times. That is the power 
of this lens, it magnifies 6 
diameters or lengths. But 
the glass being spherical 
it magnifies sidewise also ; 
BO a flat, small object 
is spread out every way 
6 times, or is enlarged In 
eurfuce 6 times 0, or 36 
times the original surface. 
As the light on the origi- 
nal object is spread out 
over many times the sur- 
face, objects to be raagnl- 
flcd should have strong 
daylight i,not the direct 
sunlight), or a good lamp- 
light. Directions are girca 
in the descriptive sheet ao- 
companying each Ameri- 
can Agriculturist Micro- 
scope. By carving the 
lens surface more, greater 
magnifying power is obtained, but with high power 
at the expense of clearness, owing to *■ spherical 
aberr;ition," or distortion, as it is termed. This 
is in part remedied by using two, three, or more 
lenses ; by a diaphragm to cut off the outside 
rays from the edges of the lens ; by an arrangement 
of layers of different glass iu the lens; by compound 
Microscopes, etc. The American Agriculturist Micro- 
scope, with its 3 lenses, its diaphragm, and special caro 
in prcfiaring and grinding the glasses, does away with 
the aberration a-* much as possible. It is a mistake to 
suppose a large Microscope, or lens, is needed for or- 
dinary use. The higher the power, the smaller must bo 
the lens, to avoid aberration. The object glass (lens) in 
our creat Micropcopo Is scarcely oneoighth of an inch 
in diameter. The Lenses in the American AgriadtvrM 
Mtcroecopeoro Jnet the size shown in the engraTingfl. 
