sit to Some of the
Petroleum-Producing Territories of the United States and
Canada.--By BOVERTON REDWOOD, F.I.C., F.C.S.--The second
portion of this valuable paper, treating more particularly
of Canadian petroleum. 9765

VI. METEOROLOGY.--The "Meteorologiske Institut" at Upsala,
and Cloud Measurements.--The methods used and results
attained in the famous Upsala observatory under Profs. Ekholm
and Hagstroem; the measurement of clouds.--1 illustration. 9764

VII. MISCELLANEOUS.--Drawing Instrument for Accurate Work.--By
J. LEHRKE.--A magnifying instrument for fine work and
measurements.--2 illustrations. 9754

Liquid and Gaseous Rings.--Notes on the production of vortex
rings.--The different aspects and breaking up of smoke
rings.--6 illustrations. 9760

Scenes among the Extinct Volcanoes of Rhineland.--The
picturesque features of the geological formations of this
region described.--10 illustrations. 9762

Shall We Have a National Horse?--An eloquent plea by RANDOLPH
HUNTINGTON for the production of a good type of animal.--Use
of the Arabian horse as an improver of the breed. 9760

VIII. NAVAL ENGINEERING.--Trial Trip of the Ohio.--The remarkable
results attained by the introduction of new boilers and
machinery in an American steamship. 9751

IX. PHYSIOLOGY.--Apparatus for Determining Mechanically the
Reaction Period of Hearing.--An interesting study of the time
of transmission of an impulse through the sensor and motor
nerves.--1 illustration. 9753

X. SANITATION.--A New Disinfector.--Description of a new apparatus
for disinfecting by superheated steam and air, with tabular
statement of elaborate tests made with it.--2 illustrations. 9754

Trees from a Sanitary Aspect.--By CHARLES ROBERTS, F.R.C.S.,
etc.--The sanitary value of trees considered by this eminent
sanitarian.--The uses and abuses of shade near houses. 9765

XI. TECHNOLOGY.--A New Alkali Process.--The Parnell & Simpson
process of making carbonate of soda, combining the features of
the Leblanc and ammonia methods. 9755

A New Process for the Distillation and Concen