are not to copy this advertisement without the express order
of_ HARPER & BROTHERS.

Address HARPER & BROTHERS, New York.

* * * * *

SCIENTIFIC AMERICAN

ESTABLISHED 1846.

The most popular Weekly newspaper devoted to science, mechanics,
engineering, discoveries, inventions and patents ever published. Every
number illustrated with splendid engravings. This publication, furnishes
a most valuable encyclopedia of information which no person should be
without. The popularity of the SCIENTIFIC AMERICAN is such that its
circulation nearly equals that of all other papers of its class
combined. Price $3.20 a year. Discount to Clubs. Sold by all
newsdealers. MUNN & CO., Publishers, No. 361 Broadway, N.Y.

* * * * *

PATENTS

Munn & Co. have also had Thirty-Seven Years' practice before the Patent
Office, and have prepared more than One Hundred Thousand applications
for patents in the United States and foreign countries. Caveats,
Trade-Marks, Copyrights, Assignments, and all other papers for securing
to inventors their rights in the United States, Canada, England, France,
Germany and other foreign countries, prepared at short notice and on
reasonable terms.

Information as to obtaining patents cheerfully given without charge.
Hand-books of information sent free. Patents obtained through Munn & Co.
are noticed in the Scientific American free. The advantage of such
notice is well understood by all persons who wish to dispose of their
patents.

Address MUNN & CO. Office SCIENTIFIC AMERICAN, 361 Broadway, New York.

* * * * *

JOHN N. McCLINTOCK & CO.,

Publishers, Printers, Stereotypers, and Electrotypers, have facilities
for doing Book Work and Job Printing.

_ESTIMATES CHEERFULLY FURNISHED._

31 MILK ST., ROOM 46, BOSTON, MASS.

* * * * *

PHOTO-ELECTROTYPE

Is the name of a new process of

_ENGRAVING BY PHOTOGRAPHY_

at less than

ONE-HALF THE COST OF WOOD ENGRAVING!

The plates are equal to the finest wood cuts, and in point of depth,
superior. We furnish an electrotype all ready for the printer's use.

We can do every description of work, Machinery, Furniture, Buildings,
Autograph Letters, Illustrations for Trade Catalogues, etc.

For specimen sheet of our work and further particulars address

PHOTO-ELECTROTYPE CO.,

63 OLIVER STREET, BOSTON.

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