At Last

A Precision Tachometer

The Van Sicklen Chronometric

The Tachometer Timed by an Elgin Watch

66

Universal in Application Reads 20 to 2500 R.P.M. on Dial Accurate Within 5 R.P.M. on Total Scale

Durable

Unaffected by Wear

Accurate as an Elgin"

For Full Description Send for Bulletin 818

Central Scientific Company

460 East Ohio Street

CHICAGO, U. S. A.

(Lake Shore Drive, Ohio and Ontario Streets)

(Being the fourth, and last, of a series of advertisements by Eimer & Amend, setting forth their RY OF THE chief attainments during the war.)

PEABODY MUSEUM

The uncommon achievements of our instrument shop during the past few years readily fall into
three groups:

FIRSTLY, the experimental work on various apparatus for use of the
American and Allied Military Forces.

SECONDLY, the rebuilding and refinishing of imported apparatus—some
pieces could not be replaced on account of the lack of essential parts, while
other pieces possessed sufficient salvage value to warrant reclamation.
THIRDLY, the building of complete instruments and apparatus to replace
those of foreign manufacture. This third class, as well as the second, was
carried to the point only where it would not conflict with the more impor-
tant business of helping to win the war.

WORK ORDERED by the Government and done directly for it was perhaps the most interest-
ing. Our files for 1917 and 1918 contain countless orders from the Gas Defense, Gas
Offense, the Army Medical Schools, the Aviation Fields, the Medical Supply Depots, etc.,
for apparatus and devices of many special kinds "as per instruction to the Machine Shop."
This labor was not limited to experimental work, but quantity production was also effected,
as evidenced by the fact that thousands of gas detectors used by the American Army on
the fields of France bore our trademark.

THE SUGAR industry was greatly inconvenienced by the inability to procure French or German polariscopes. When the consequences had assumed a serious aspect, we undertook to remodel a Schmidt & Haensch instrument, including repolishing, cementing and repairing of the prisms. The results was so highly pleasing to our customer that we secured a continuous flow of orders of this kind from all over the sugar-producing sections of the United States, Cuba, and Porto Rico. To the best of our knowledge, all the polariscope observation tubes produced in the world during the past two years (except those, if any, turned out by our enemies) were made by us.

AMONG precision instruments of similar class which we have taken the time to dismantle and remodel, let us mention Wanner pyrometers and Zeiss microscopes, including their objectives.

WE HAVE manufactured COMPLETELY Beckmann boiling point and freezing point apparatus; Duboscq colorimeters, quite like the original French, and, we think, better; Juerst ebullioscopes, to replace the Salleron; and also a number of other intricate physical apparatus. IN ADDITION to these, we have maintained and increased our normal output of such well known specialties as the three types of Young's specific gravity instruments (two styles embodying displacement plummets of incomparable accuracy) excelling in sensibility the highest class of analytical balance; Kimley Electro-Analysis apparatus; Gramercy Stirrers, and many others.

THE CAPABILITIES and the facilities that raised this shop and its work above others of its kind are now available for the solution of problems like in nature to those indicated by the foregoing resume.

EIMER & AMEND

NEW YORK AND PITTSBURGH

Your Laboratory Needs

of every description can be met by us to your entire
satisfaction. We have purchased from the Bausch
& Lomb Optical Company their full stock of high-
grade Chemicals, Chemical and Bacteriological
Apparatus, Reagents and other Laboratory Sup-
plies, and are prepared to give your orders prompt

attention.

Originally laboratory workers ourselves, we have
been in intimate touch with laboratory conditions for
several years and are thus peculiarly qualified to
serve you.

Practically the entire Bausch & Lomb organization
in the Chemical Department accompanied the stock,
enabling us to begin operations without interruption.
We shall always maintain a carefully assorted stock of
recognized goods, which can be guaranteed without
reservation, while our Glass Blowing facilities will
permit the prompt execution of your orders for
special apparatus and repairs.

Catalogs are now in course of preparation for early
distribution. In the meantime we are glad to sub-
mit quotations on any laboratory equipment you may
require. Let us prove to your satisfaction that we
can give you the service you are looking for and
have a right to expect.

The Will Corporation
Rochester, N. Y.

A New Agricultural Text

FARM HORTICULTURE

By GEORGE W. HOOD, M.Sc.

Associate Professor of Horticulture, University of Nebraska

12mo, 339 pages with 142 engravings. Cloth, $2.50 net

Written primarily as an elementary text, arranged and developed to meet the needs of the undergraduate collegiate student, as well as those studying agriculture in the secondary agricultural schools. Judging by the letters received from Professors of Agriculture in our leading colleges, the author has succeeded in his aim to produce a thoroughly practical book that would fully meet these requirements.

Teachers of agriculture and horticulture will find it suitable as a text to cover the general field. It gives information about those practices which many people desire but which cannot be found in any single text. It will be a guide to any farmer or city man on the important subjects in horticulture. The diagrams and plans for gardens of varying sizes are most helpful and clear, as are the chapters on The Seed and Its Needs, Cultivation and Tillage, Budding and Grafting, Marketing, the various Pests and how to Combat Them. Interesting also are the special chapters devoted to the Strawberry, the Bush Fruits, the Brambles, the Grape, the Pome Fruits, the Stone Fruits, the Citrus Fruits and Beautifying the Home Grounds.