1877 .] 
AMERICAN AGRICULTURIST. 
453 
so complete and desirable, has hitherto been offered to 
the general public at so low a price as $3.50. With 
the improvements in mode o£ manufacture, and 
the great number contracted for, this instru¬ 
ment will be supplied at retail for only $1.50. 
HUT to every actsial subscriber 
to the American Agriculturist fosr 
1878, one of these ^Horoscopes will 
be supplied complete for 4© cents 
above the subscription price, and 
to the club subscribers at only S3 
to 35 cents above the club subscrip¬ 
tion rates win'll taken at the office 
or its delivery provided for. The 
Publishers will pay for the addi¬ 
tional cost of manufacture—a large 
sum in the aggregate. 
HEBE ABE THE TEEMS : 
(The American Agriculturist will be 6ent post-paid 
from receipt of subscription to the end of 1878. The 
Microscopes will be delivered as provided below.) 
One Subscription and One Microscope.$2.00 
2 Subscriptions and 2 Microscopes.$3.80 ($1.90cach.) 
3 Subscriptions and 3 Microscopes.$5.25 ($1.75 each.) 
4 Subscriptions and 4 Microscopes.$6.60 ($1.05 each.) 
5 to 9 Subscribers and 1 Microscope each.$1.60 each. 
10 to 19 Subscribers and a Microscope each $1.55 each. 
20 Subscribers and a Microscope each.$1.44 each. 
Or, in clubs, of 20 and upwards, $1.10 for each subscrip¬ 
tion, and SSJtfc. for each Microscope, (that is, $1 extra for 
every three Microscopes, in all clubs of twenty or more.) 
It will thus be seen that the $1.5© Micro¬ 
scope (really worth at least $2.5©, as compared 
with anything ever before offered) can be obtained 
by any regular subscriber to the Am. Agriculturist 
for 1878, and by such only, for the small extra cost 
of only 33 to 40 cents, as above. This is surely get¬ 
ting double value for one’s money, and more. 
Delivery of the Microscopes. 
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 stated, which is 
only a part of the actual cost of manufacture alone. 
II. Whenever 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 carriage but 
a few cents each. We will pack them safely with¬ 
out charge, and forward them in any way directed, 
on receipt of the names for whom, they are to be 
supplied, with the small extra sum for the Micro¬ 
scopes 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 receipt 
of 15 cents for each Microscrope, for payment of 
carriage. We can only promise this for the present 
year, as we have not yet been able to make express 
and other arrangements extending beyond Decem¬ 
ber 31,1877. If this can be continued, it will be 
announced hereafter. 
IV. Our subscribers in foreign countries, not 
named above, will need to provide for, and direct 
how the Microscope shall be forwarded to them. 
Any Subscriber already on our books for 1878, can 
have a Microscope by remitting 40 cents, adding 
the 15c. 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 331 cents each, and cost of carriage to the 
address, if to be sent prepaid. 
N. I*.—The Microscope is designed for ait 
subscribers on our books for the American Agricul¬ 
turist for all of 1878, no matter from whom received. 
We repeat, that the receipt of 40 cents from any 
subscriber for 1878 will entitle him or her to one of 
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 deliver it. 
Order of Delivering Microscopes. 
They arc 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 machinery for making them can be 
constructed—probably several thousands a week. 
IJ2F” They will be sent out in the order of receipt 
of names—first come, first served. 
Fig. 4.— GLASS PLATES. 
The CJeneral Premium List not 
Affected by the Microscope 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, will 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 $1 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 $1.00 or 81.10 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 Hew 
Microscope. 
It is, of course, unnecessary among our own readers to 
enforce or fortify wliat we say concerning the Micro¬ 
scope ; yet it may interest some to read what others think 
of it. We sent one of the first complete instruments to 
Prof. Rice, Professor of Geology and Natural History, 
who has classes in Microscopy, and largely uses a variety 
of these instruments. The. Microscope next went to 
Prof. Atwater, well known to our readers by his contri¬ 
butions to this Journal, and as Director of the first suc¬ 
cessful Agricultural Experiment'Statioii in this country: 
Wesleyan University, I 
Middleton, Conn., Nov. 12,1877. ) 
Orange Judd Company , New York: 
Gentlemen:—1 have examined with great pleasure the Mi¬ 
croscope devised by you, and made under ycur auspices, 
and called the “American Agricultural Microscope.’’ 
It is a beautiful little instrument. Its Lenses , singly and in 
combination , give a range of power from seven to about 
twenty-four diameters. It can be used both with reflected 
and with transmitted light. If you can sell it far Two Dol¬ 
lars, you will thereby render a real service to the community. 
1 know of no Microscope sold so low as $2 which is equal, or 
nearly equal, to this in excellence. 'It is not a mere toy, but 
is well adapted for use in botanical analyses, and other sci¬ 
entific studies, which require the aid of a simple form of 
Microscope. Yours truly, Wm. North Eice. 
_ 1 have examined your Microscope with great satisfac¬ 
tion, subscribe fully to what Prof. Rice says of it, and rec¬ 
ommend it heartily, not only to Farmers, for .examining 
fertilizers, feeding materials, and seeds that are liable to 
adulteration, dairy products, plants, and minute animal or¬ 
ganisms by which they are apt. to be injured, but also to all 
intelligent people who wish a Microscope, and can not afford 
an expensive one. It is decidedly the best thing for the price 
of $2 that I have ever seen, and I hope it will be widely in¬ 
troduced and used. Yours respectfully, W. O. Atwater. 
Some Wonders of the Microscope. 
The unaided eye takes a very limited range of objects. 
To see the whole of anything a hundred feet square only, 
it must be so distant that its details of surface arc imper 
ceptible. An object a hundredth part of an inch in di¬ 
ameter becomes a mere dot to the eye. Of the “ in¬ 
numerable stars,” the eye sees hut a thousand above 
tlie horizon. The great telescope at Washington reveals 
50,000,000 stars, and probably there are millions and 
billions more still undiscovered; indeed, is there a place 
where there are no stars beyond ? Eacli star is believed 
to beau immense sun, with great planets or worlds revolv¬ 
ing around It — Go the other way;—there aroplants and 
animals, too small for us to see—millions, millions of bil¬ 
lions times more numerous than all we can see. Last 
summer, with our large microscope we examined and 
measured animals (auimaiculse) 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 because it is so fine, contains in a single inch 
the skeletons of some 40,000,000,000 (forty billions!) of 
organic plants that have lived and grown. The Micro¬ 
scope shows that on the duckweed there are perfect 
animalcul® (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 us. Such an instru¬ 
ment is now obtainable by any one, as detailed mother 
columns of this paper. 
How a Microscope Magnifies- 
The illustration (fig 7) will explain this. L is a single 
glass lens with curved surfaces. A ray of light going from 
thetopof thoarrowisbentdowmvard 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 upward, and the eye sees this ray in the 
direction of the lower dotted line. Eays from all other 
points of the arrow, are similarly bent, and if the 
glass he perfectly formed, they will all meet in tho 
eye, and the length of the arrow will thus bo greatly 
magnified, and its minute points be clearly seen. In 
the engraving, the arrow is enlarged in length only 6 
Hi times. That is the power 
of this lens, it magnifies 6 
diameters or lengths. But 
the glass being spherical 
it magnifies sidewise also: 
so a flat, small object 
is spread out every way 
6 times, or is enlarged in 
surface 6 times 6, 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 magni¬ 
fied should have strong 
daylight (not tho direct 
sunlight), or a good lamp¬ 
light. Directions aro given 
in the descriptive sheet ac¬ 
companying each Ameri¬ 
can Agriculturist Micro¬ 
scope. By curving tho 
lens surface more, greater 
Fig. 7. 
magnifying power is obtained, but with high power 
at the expense of clearness, owing to “ spherical 
aberration,” 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 in the lens; by compound 
Microscopes, etc. The American Agriculturist Micro¬ 
scope, with its 3 lenses, its diaphragm, and special care 
in preparing and grinding the glasses, does away with 
the aberration as 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 be 
the lens, to avoid aberration. The object glass (lens) in 
onr great Microscope is scarcely one-eighth of an inch 
in diameter. The Lenses in the American Agriculturist 
Microscope aro Just the size shown in the engravings. 
