I. BIOGRAPHY.--CHARLES GOODYEAR.--The life and discoveries of
the inventor of vulcanized India rubber, with portrait.--1
illustration
II. BIOLOGY.--Can we Separate Animals from Plants?--By ANDREW
WILSON.--A debated point well discussed.--The bases on which
distinctions must be drawn
III. ELECTRICITY.--A New Electric Ballistic Target.--A target
for investigations of the velocity of projectiles, now in use at
the United States Military Academy, West Point, N.Y.--1
illustration.
Electric Erygmascope.--An electric lighting apparatus for
examining earth strata in bore holes for geologists' and
prospectors' use.--1 illustration
The Electro-Magnet.--By Prof. SILVANUS THOMPSON.--Continuation
of this exhaustive treatise, giving further details on special
points of construction.--1 illustrations
IV. ENTOMOLOGY.--Potash Salts.--The use of potash salts as
insecticides, with accounts of experiments
The Outlook for Applied Entomology.--By Dr. C.V. RILEY, U.S.
entomologist.--The conclusion of Prof. Riley's lecture, treating
of the branch of entomology with which his name is so honorably
associated
V. INSURANCE.--The Expense Margin in Life Insurance.--Elaborate
review of the necessary expenses of conducting the insurance of
lives, with tables and calculations
VI. MATHEMATICS.--The Trisection of Any Angle.--By FREDERIC R.
HONEY, Ph.B.--A very ingenious demonstration of this problem,
based on the properties of conjugate hyperbolas