III. PHYSICS, ELECTRICITY, ETC.--Electric Power.--The nature and uses of
electricity.--Electricity vs. steam.

On the Method of Obtaining and Measuring Very High Vacua with a
Modified Form of Sprengel Pump. By Prof OGDEN N. ROOD.--4 figures.--
Apparatus for obtaining vacua of one four hundred-millionth of an
atmosphere--Construction.--Manipulation.--Calculations.--Results

IV. ART, ARCHITECTURE, ETC.--Old Wrought Iron Gates, Guildhall.
Worcester, England. 1 figure.

The French Crystal Palace, Park of St. Cloud, Paris. 1 full page
illustration.

Suggestions in Architecture. A Castellated Chateau. Perspective and
plan. Chateau in the AEgean Sea.

V. HYGIENE AND MEDICINE.--Hydrophobia Prevented by Vaccination.

On Diptera as Spreaders of Disease. By J. W. SLATER.

On the Relations of Minute Organisms to Certain Specific Diseases.

VI. ASTRONOMY--The Centenary of the Discovery of Uranus. By F. W. DENNING.
2 figures. Approximate place of Uranus among the stars at its
discovery, March l3, 1871.--Orbits of the Uranian Satellites.

VII. BIOLOGY, ETC.--The Varying Susceptibility of Plants and Animals to
Poisons and Disease.