THE ARTIFICIAL PRODUCTION OF DIAMOND. 
81 
It is probable that some meteoric matter may have been melted by collision or 
ejected into space in a molten state and cooled by radiation, and that under such 
conditions the absence, or diminution, of occluded gases miglit be a factor conducive 
to the crystallization of carbon. 
One of the 4-inch diameter pressure moulds (fig. lO) was used in a preliminary 
experiment as the container. The crucible was turned out of a l|^-inch carbon rod, 
and so formed on a stem that the electric current heated the bottom and sides 
equally. The cover was similarly formed and its holder was electrically connected 
with the container, but free to move vertically and to rest its weight on the crucible. 
Ram 
electrical connection to the container being made by a layer of brass or iron turnings 
resting on the holder. A current of 1000 amperes at 16 volts sufficed, and the 
temperature was observed through a glass window at the side of the container. 
The crucible was charged with reduced iron and lampblack. The Geryk pump 
evacuated the container to f-inch mercury absolute; current was turned on for 
15 seconds, the vacuum fell to 3 inches, when it had risen again to |-inch current 
again turned on. This was repeated three or four times, finally current was 
applied for 30 seconds and the vacuum again fell to 3 inches. The gas was drawn 
off and collected, it amounted to a total of ^ gallon at atmospheric pressure and 
