ning, Return of Gold
from the Diggings, Mortality, Cost of Living, etc., I refer the reader
to my book on this subject entitled "Klondyke Facts," a work of about
224 pages. It is published in paper covers at 50 cents a copy with maps
and illustrations, and is sent postpaid by the publishers on receipt of
50 cents.

AMERICAN TECHNICAL BOOK CO., 45 Vesey Street, New York, N.Y., U.S.A.

* * * * *

*ABC of Electricity*. Now in its 62d thousand. By WM. H.
MEADOWCROFT. 1 volume, 12mo, cloth, 50 cents Fully illustrated.

This excellent primary book has taken the first place in elementary
scientific works. It has received the endorsement of Thomas A Edison. It
is for every person desiring a knowledge of electricity, and is written
in the simplest style so that a child can understand the work. It is
what its title indicates, the first flight steps in electricity.

*Scholars' A B C of Electricity*. By WM.H. MEADOWCROFT. One volume,
12mo, illustrated, cloth, 50 cents.

The author of this work has designed it for the use of teachers and
scholars. A large number of simple experiments have been added, with
notes relative to the work. It is the primary book for school use.

_A Most Important Work of General Interest_.

*The X Ray; or, Photography of the Invisible and its Value in Surgery*
By WILLIAM J. MORTON, M.D. Written in collaboration with EDWIN W.
HAMMER. 1 volume, 12mo, cloth and silver, 75 cents; paper, 50 cents.

Everyone has been waiting for this work to give full information of
Professor Rontgen's marvellous discovery. The work explains in clear and
simple style how these extraordinary pictures are taken through solids.
Full description is given of the apparatus used, and the text is
profusely illustrated with half tone illustrations giving fac-simile
copies of the pictures taken from the negatives of the author. The
subjects are varied.

*The A B C of the X Ray*. By WM.H. MEADOWCROFT. 1 volume, 12mo, cloth
and gold, 75 cloth; paper, 50 cents.

The first primary work on the subject. A book for the people. The author
of "A B C of Electricity," showed clearly in that work his ability to
explain a technical subject for the laymen who know nothing of
scientific terms. He has written this work about the X Ray in his usual
clear and simple style, and a wide circulation of this useful book is
assured. The texts of the author is beautifully embellished with fine
engravings, and nothing is