d the
largest patent practice in the country. We file thousands of
applications for patents every year. Our system is so perfected that
every case receives the best of attention and is prepared by experts who
have had special training in handling every class of invention.

SEND SKETCH. If you will send us a sketch, no matter how crude, we will
give you a fair and candid opinion as to whether it is probable a patent
can be obtained. All matters of this kind are strictly confidential and
the description and sketches will be dated and placed in our secret
archives for future reference. This service and our Hand Book on Patents
are free.

QUALITY. The quality of our work has given us an unrivaled reputation
among Patent Attorneys and we are the recognized American attorneys for
many leading Foreign Patent Solicitors. Our staff consists largely of
Examiners from the United States Patent Office, who are therefore
familiar with the latest procedure and the best practice. Our draftsmen
are all expert mechanical constructors who are able to show the
invention in operative form.

FREE NOTICE. All patents secured through our house receive a free notice
in the SCIENTIFIC AMERICAN. No better or more economical method of
introducing your invention to the attention of the public could be
devised.

We are prepared to conduct Interference Proceedings, give Validity
Opinions, draw up contracts and attend to all branches of legal work
connected with Patents, Trade Marks, etc.

* * * * *

_WASHINGTON OFFICE_
625 F STREET, N. W.
WASHINGTON, D. C.

MUNN & CO., _Attorneys_
361 Broadway, New York, N. Y.

SCIENTIFIC AMERICAN

_The Weekly Journal of Practical Information_

THE SCIENTIFIC AMERICAN, founded over sixty-seven years ago (1845), has
become to-day the official organ of those people who really do things,
and want to know what others are doing; it is for the one whose whole
business success depends upon these great mechanical, chemical,
electrical and engineering achievements, which are rapidly and surely
making this nation.

THE SCIENTIFIC AMERICAN is the authority; it is always up to date; and
gives its readers the first news as well as the most complete news of
any new development in the Sciences, Arts, Manufactures, etc. Some of
the department features are:

HANDY MAN'S WORKSHOP.--In this department those who use tools either for
pastime or profit will find suggestions which will be h