This section is from "Scientific American Vol. XLIII. No. 25", by Munn & Co. Also available from Amazon: Scientific American Science Desk Reference.
Specifications of the conditions and requirements relating to proposals, samples, contract, etc., as well as forms of proposal, will be furnished on application by letter to the Second Assistant Postmaster General.
No proposal will be considered unless it shall have been submitted in accordance with such specification and forms.
The contracts which may be made will be in conformity to the specifications and the accepted proposal. But the right is, however, reserved to reject any and all of the proposals.
JAS. N. TYNER,
Acting Postmaster General.

Foot and Power Lathes, Drill Presses, Scrolls, Circular and Band Saws, Saw Attachments, Chucks, Mandrels, Twist Drills, Dogs, Calipers, etc. Send for catalogue of outfits for amateurs or artisans.
H. L. SHEPARD & CO.,
331, 333, 335, & 337 West Front Street,
Cincinnati, Ohio.
HUB MACHINERY. - HUB TURNING, HUB MORTISING, and Hub Boring Machines. Send for price list and circulars. DAVID JENKINS, Sheboygan, Wis.
For steep or flat roofs. Applied by ordinary workmen at one-third the cost of tin. Circulars and samples free. Agents Wanted. T. NEW, 32 John Street, New York.
| PATENT COLD ROLLED SHAFTING. |
The fact that this shafting has 75 per cent. greater strength, a finer finish, and is truer to gauge, than any other in use renders it undoubtedly the most economical. We are also the sole manufacturers of the Celebrated Collins' Pat. Coupling, and furnish Pulleys, Hangers, etc., of the most approved styles. Price list mailed on application to
JONES & LAUGHLINS, Try Street, 2d and 3d Avenues, Pittsburg, Pa.
190 S. Canal Street, Chicago, Ill.
Stocks of this shafting in store and for sale by FULLER, DANA & FITZ, Boston, Mass. Geo. Place Machinery Agency, 121 Chambers St., N. Y.

Complete sets of
CASTINGS
for making small Model steam Engines 1-1/2 in. bore, 3 in. stroke, price,$4; ditto 2 in. bore, 4 in. stroke, price, $10, same style as cut. Gear Wheels and Parts of Models. All kinds of Small Tools and Materials. Catalogue Free. GOODNOW & WIGHTMAN, 176 Washington Street, Boston, Mass.
in the market to London, Berry & Orton, Phila., Pa.

New and Improved Patterns.
Send for new illustrated catalogue.
Lathes, Planers, Drills, etc.
NEW HAVEN MANUFACTURING CO.,
New Haven, Conn.
Send for Catalogue.
R. SIMPSON, 132 Nassau St., N. Y.


The New Economizer, the only Agricultural Engine with Return Flue Boiler in use. Send for circular to Porter MFG. Co., Limited, Syracuse. N. Y.
G. G. YOUNG, Gen. Agt., 42 Cortland St., New York.
Inside Page, each insertion - 75 cents a line.
Back Page, each insertion - $1.00 a line.
(About eight words to a line.)
Engravings may head advertisements at the same rate per line, by measurement, as the letter press. Advertisements must be received at publication office as early as Thursday morning to appear in next issue.
The publishers of this paper guarantee to advertisers a circulation of not less than 50,000 copies every weekly issue.
A special Holiday number, designed for boys and girls everywhere, whether regular readers of the magazine or not; - the best, and, by reason of its immense edition, 105,000, the cheapest Christmas book published, Price 30 cents.
A brilliant Holiday cover; superb pictures by the best American artists; a capital acting operetta for children "The Land of Nod," with words and music; a splendid story by Washington Gladden, "A Christmas Dinner with the Man in the Moon," the illustrations of which rival Dore's; "King Arthur and his Knights," by Sidney Lanier; one of Frank R. Stockton's inimitable FAIRY STORIES; the "Treasure Box of Literature," etc., etc.; - in all, thirty-three departments and contributions.
A Grand Holiday Gift-Book of 100 Pages, printed on tinted paper, illustrated with scores of charming pictures, for only 30 cents. Ask for the Christmas (December) St. Nicholas. Four editions of last year's Holiday number were demanded. For sale everywhere. Subscription price, $3.00 per year.
Scribner & Co., 743 Broadway, N. Y.

For a Machine that will
Saw as Fast and Easy
as this one.
This is the King of Saw Machines. It saws off a 2 foot log in 2 minutes. 20,000 in use. The cheapest machine made, and fully warranted. Circular free. United States Manufacturing Co., Chicago, Ill.
on the goods whenever you buy
37 & 38 PARK ROW, NEW YORK.

Watchman's Improved Time Detector, with Safety Lock Attachment, Patented 1875-6-7. Beware of Infringements. This Instrument is supplied with 12 keys for 12 different stations. Invaluable for all concerns employing night watchmen. Send for circulars to E. IMHAUSER, P. O. Box 2875. 212 Broadway, New York.
 
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