348 Chronicles of Science. | April, 
intended to apply them to heating steam-boilers and welding articles 
of wrought iron. 
The safety of these furnaces, their regularity and self-supplying 
action, and perfect freedom from dust and smoke, render them advan- 
tageous in certain processes, such as enamelling, annealing, &c., where 
cleanliness and unitormity of heat are required. Their high degree of 
heat without the aid of a blast results from the very rapid and perfect 
mixture of the air and gas, and the combustion being consequently 
effected and concentrated in a very small space. 
To provide for cases where gas is not available for the production 
of these high temperatures, and a more cleanly and manageable 
source of heat is required than that afforded by a coke furnace, 
Mr. C. Griffin,* has constructed an oil lamp for use with an 
artificial blast of air, which is not only as powerful in action as the 
best gas furnaces, but almost rivals them in convenience and economy. 
The fuel is the more volatile kind of mineral oil of the specific gravity 
‘750; every precaution is taken to prevent any danger of explosion 
by the sudden or accidental ignition of the vapour. The flame pro- 
duced in this furnace is as clear as that of an explosive mixture of air 
and coal gas, and it is perfectly free from smoke. No chimney is 
required. ‘The power of the furnace is very great: starting with a 
furnace quite cold it will melt one pound of cast-iron in 25 minutes, 
14 lb. in 30 minutes, 4 lbs. in 45 minutes, and 5 lbs. in 60 minutes ; 
the cost of the latter experiment being about 9d. for oil. In all cases 
where gas cannot be obtained as a fuel for such operations, this oil- 
lamp furnace cannot fail to prove of very great value. 
Oxygen, that fierce supporter of combustion at ordinary pressures, 
would have its energy increased to an inconceivable extent if used in 
a highly-condensed form. An observation of Dr. Frankland has 
shown that under this condition a solid mass of iron is almost as 
inflammable as phosphorus in the ordinary state of the atmosphere. 
During some experiments at the Royal Institution he was condensing 
oxygen gas into the strong iron receiver of a Natterer’s apparatus, and 
had got the pressure up to 25 atmospheres when the vessel burst with 
a loud explosion, sending a shower of brilliant sparks in every 
direction. Upon subsequent examination it was seen that the whole of 
the interior of the receiver and the solid steel plugs had been eaten 
away to the depth of an eighth of an inch, and was covered with a fused 
mass of oxide of iron. The heat evolved in the compression had 
evidently ignited the oil used to lubricate the piston; this immediately 
caused the combustion of the iron which, in the atmosphere of com- 
pressed oxygen, proceeded with great intensity ; there can be scarcely 
a doubt, the Professor considers, that had a union joint not given way, 
and thus furnished an outlet for the compressed gas, the latter would in 
a few seconds more have converted the receiver into a most formidable 
shell, the almost inevitable explosion of which would have scattered 
fragments of intensely-heated and molten iron in all directions. 
The observations of Professor Tyndall on the physical properties 
* ¢Chemical News,’ vol. ix. p. 3. 
