19a 
Steam Ejigine. 
practical utility will admit, which must necessarily render 
it of great advantage ; as the simplicity of its parts make 
it nearly impossible to be out of order with a very mode- 
rate degree of management. The following description 
and reference to the plate will explain the nature of this 
engine. 
I am, Sir, 
Your much obliged humble servant, 
MATHEW MURRAY. 
Leeds j May Ith^ 1805. 
Description of a Portable Steam Engine, — Plate L 
AA. Represents the ground or floor on which the en- 
gine stands. 
B. Section of a recess made in the ground for the beam 
O to work in. 
C. Iron cistern resting upon the ground or floor co- 
vering the recess for the beam. 
D. An opening in the floor to admit a boy to oil the 
centres of the beam. 
E. A double steam cylinder, having an upright pipe 
in the intermediate space, which effects a communication 
between the top and bottom, and the valve box G. 
F. A steam pipe that communicates with the boiler 
through which all the steam passes and surrounds the in- 
ner cylinder in its way to the valve box, prior to its appli-« 
cation against the piston. 
G. The valve box fixed upon a projection from the 
cylinder bottom, having an opening or connection with 
the interval between the two cylinders. In this opening 
is a regulating valve for adjusting the quantity of steam 
(tliat acts against the piston) in its passage through the 
valve box. There are also three other openings in the 
bottom of this valve box, one of which connects with the 
top of the cylinder by the pipe in the intermediate space, 
the second with the bottom, and the third with the educ- 
