3sZ8 Mr Perkins’ method of applying his New Invention of 
On the Smelting of Copper-ores. Stockholm, 1766. 
On the Uses of the Stones which are furnished by the Quarries 
of Sweden. 1771. 
On the Resources of different Provinces of Sweden. 1773. 
Tables of the Population and Manufactures of Westro-Both- 
nia. Stockholm, 1801. 
Essay of a Mineralogical Description of Lapland and Westro 
Bothnia. Stockholm, 1801. 
Lastly, Mineralogical Maps of the principal Provinces of the 
South of Sweden. 
Art. XXII. — Account of Mr Perkins’ method of applying his 
New Method of Generating Steam to the Boilers of ordi- 
nary Steam-Engines. 
Having in our last Number given a very full, and we trust 
perspicuous, account of Mr Perkins’ new Steam-Engine, we shall 
now proceed to lay before the reader Mr Perkins’ own account 
of his method of applying the new principle to steam-engines of 
the old construction. This account is taken from the specifi- 
cation of his patent, which is now open to the inspection of the 
public. 
In order, however, that a correct idea may be formed of the 
original principle itself, we shall prefix Mr Perkins’ own ac- 
count of the generator, although we have already given a ge- 
neral description of it in our last Number. 
66 Plate IX. Eig. 1. represents the general construction of 
the apparatus ; a, a } a, is the generator shewn in section. It is 
a strong cylindrical vessel, made of metal, about three inches 
thick in every part, which may be a guide to the comparative 
dimensions of the other parts of the apparatus. This vessel is 
to be filled with water, and heated by a furnace circumscribing 
it On the top of the generator there is an escape-valve h , 
pressed down by the weighted lever c, the pressure being ad- 
justable by the shifting of the weight. The valve opens to the 
steam-pipe d, which is to be supposed as proceeding to the 
working piston of the engine. The lateral pipe e , extending 
from the generator, is merely for the purpose of safety ; and at 
