Chapter III: TECHNOLOGY.--Alizarine Dyes.--Process of dyeing.--Recipes for

various colors.

Cement Paving.--Composition made by the Wilkes' Metallic
Flooring Company.--Other compositions.

A New Bleaching Process.--The "Mather-Thompson" system.

Instruments for Drawing Curves.--By Prof. C.W. MACCORD--1.
The Hyperbola--2 figures.

Experiments with Fibers.--By Dr. THOS. TAYLOR.--Detection of
Fraud.--Method employed.--Cotton mixed with linen.--Experiments
with flax.--Wool tested with acid.--Tests of dyed black silk.

Orthochromatic Plates.--By CH. SCOLIK.

A New Photographic Apparatus.--With engraving.