355 
is driven off by stacking the peat against an air-chamber, 
heated by the surplus heat from the furnaces. 
The carbonising furnaces are of wrought iron, pyramid- 
ically shaped, the base measuring about 5 feet ; they run on 
wheels, and are filled from the top ; the mass is ignited by the 
introduction of some burning peat. In the course of a few 
hours the peat becomes perfectly carbonised, and the damper 
attached to the furnace being closed, the charcoal is allowed 
to cool. 
Peat may also be carbonised in large cylindrical retorts, 
set perpendicularly, capable of holding four tons of material. 
The liquid and gaseous products are collected through a pipe 
passing off at the upper end, connected with a refrigeratory, 
and the charcoal is discharged through an aperture at the 
bottom. This plan is adopted in France. It is said that the 
charcoal made in heaps or mounds is the best for metallur- 
gical purposes, and that prepared in furnaces and retorts is 
best for deodorising uses and manure. 
Mr. Vignolles, C. E., has patented a process for carbonising 
peat by means of superheated steam. The dried peat is 
placed in large iron vessels, into which steam, heated to from 
450° to 600° Fahrenheit, is introduced. The steam, in its exit 
from an ordinary boiler, is made to traverse a coil of pipe 
heated in a furnace, and thus acquires a temperature sufficiently 
high to effect the carbonisation of the peat. The charcoal is 
withdrawn into suitable receiving vessels, placed underneath 
the carbonising apparatus. This process is carried out on 
the large scale at Friesack, in Prussia. It is a modification 
of my friend M. Violette's process, for the carbonisation of 
wood for the manufacture of gunpowder. 
Many and various processes for carbonising peat have 
been patented in this and other countries, but time will not 
allow of my noticing them on the present occasion. I now 
proceed to mention sojne of the applications of charcoal. 
b b 2 
