S98 Mr Aikin’s Method (^Protecting Steel Articles. 
be lengthened by screwed joints, or other obvious means. At 
the lower end of the pole is a lever c, which may be fixed by a 
screw and socket to any part of the pole. The lever d, of the 
moving blade has a spring under it, to keep it open, and 
from the end of d, a string passes over the pulley e, to the 
handle c. By means of the arch and joint at jfl the cutters may 
be set at any required angle. 
, When the fruit-gatherer is raised, so that the stalks of the 
fruit are included between the cutters, the string ce is pulled ; 
the stalks are cut, and the fruit drops into the basket h. 
ll. Mr Amm^s Method (of Protecting Steel Articles from Rust 
by a Coating of Caoutchouc. 
It occurred some time ago to Mr Arthur Aikin, the ingenious 
Secretary to the Society of Arts and Manufactures, that melted 
caoutchouc would be found to preserve the surface of iron goods 
from oxidation, by the action of the atmosphere, in consequence 
of its undergoing almost no chemical change when exposed to 
the air, — its treacly consistence under ordinary degrees of heat, 
— its powerful adhesion to iron or steel surfaces,-^and the faci- 
lity with which it can be removed by a soft rag and a piece of 
stale bread. 
The truth of this conjecture was afterwards established by 
direct experiment. Plates of iron and steel that had one-half 
of their surfaces covered with caoutchouc, remained unoxidated, 
while the unprotected parts were almost wholly corroded by ex-^ 
posure for five or six weeks in a laboratory. 
The caoutchouc must be melted in a close vessel, to prevent 
it from being charred, and from taking fire. It melts nearly at 
the temperature ^t which lead fuses ; and, when in a fluid state, 
it must be stirred with a horizontal agitator, by means of a 
handle rising aboye the vessel, to prevent the caoutchouc from 
burning to the bottom. 
Mr Aikin communicated this useful discovery to Mr Perkins, 
who employs it in preserving his engraved steel blocks, plates, 
rolls and dies. Mr Perkins iipptPved the process, by incorpo- 
rating the caoutchouc with oil of turpentine, which makes it more 
easily^ applied, and which dries into ^ firm varnish, inaccessible 
