Hydraulic Mining in California.--By GEO. O'BRIEN.


III. TECHNOLOGY.--Emerald Green: Its Properties and
Manufacture.--Use in wall paper.--ROBERT GALLOWAY.

Charcoal Kilns.--Extra yield.--2 figures.


IV. ARCHITECTURE--Entrance, Tiddington House, Oxon.--An
engraving.


V. ELECTRICITY, LIGHT, HEAT. ETC.--The Temperature of the
Earth as shown by Deep Mines.

New Arrangement of the Bichromate of Potash Pile.--3
figures.

The Distribution of Electricity by Induction.--1 figure.

Electricity Applied to the study of Seismic Movements.--Apparatus
for the study of horizontal and vertical seismic
movements, etc.--8 figures.

New Accumulators.--3 figures.

Industrial Model of the Reynier Zinc Accumulator.