56 
BLAXLAND’S PROPELLER. 
its centre, and the box is thereby kept full of oil, in which the wheels continually 
work. 
This contrivance has been applied practically by Messrs. Penn and Son, of 
Greenwich, in a vessel called the ‘ Infant Prince; ’ of the dimensions and machinery 
of which we have been furnished with the following particulars. 
DIMENSIONS OF VESSEL. 
Length extreme . . . . . . • 54 feet. 
Breadth ........ 10 do. 
Draught of water ....... 2 feet 8 inches. 
This vessel is propelled by two non-condensing engines on the vibrating principle, 
for which Messrs. Penn have justly acquired much celebrity: the cylinders are 
8 inches in diameter, and the length of stroke 12 inches; they make from 75 to 
80 strokes per minute, and this velocity is multiplied four times by the bevel 
wheels, so that the propeller makes from 300 to 320 revolutions per minute; the 
diameter of the propeller is 2 feet 4 inches, and its periphery forms an angle 
of 60° with the axis. 
On application to Mr. Penn, jun., that gentleman placed the vessel at the writer’s 
disposal for an experiment. The speed on that occasion was about 10 miles per 
hour, with steam of a pressure of about 40 lbs. per square inch. It should be 
stated that the rudder j is not used in this vessel; and the operation of steering 
is therefore entirely performed on changing the position of the propeller by the 
worm wheel already described. 
blaxland’s propeller.