386 Transactions. — Miscellaneous. 



depend, as well as the safety of an enormous value in ships 

 and steamers using charcoal as an insulator, but that my 

 opinion is supported by the investigations of many men of 

 high rank in the scientific world, as well as by well-authenti- 

 cated instances of fires occurring from the spontaneous com- 

 bustion of charcoal, both ashore and afloat. 



The first authority I cite is that of Mr. F. C. Moore, pre- 

 sident of the Continental Insurance Company, New York. In 

 his work entitled "Fires," published at New York (1877), Mr. 

 Moore says, " Charcoal will burn when pulverised, or when 

 finely divided in heaps. Twenty or thirty hundredweights of 

 charcoal, in a state of minute subdivision, are almost certain 

 to burn spontaneously. In an experiment made in France, 

 under Government supervision, it was found that the inflam- 

 mation occurs towards the centre of the mass, at about five or 

 six inches below the surface. The temperature is constantly 

 higher at this point than any other. In another instance, 

 where small charcoal was thrown into a heap 10ft. square and 

 4ft. deep, containing two or three tons of charcoal, the tem- 

 perature had increased in three days to 90 c , though at first 

 only 57° (that of the air at the time). On the sixth day it was 

 150°, and on the seventh clay combustion had occurred in 

 several places. The charcoal had been made ten or twelve 

 days before the experiment took place, had been freely exposed 

 to the air, and was not in any sense what is known as ' freshly- 

 burned' charcoal. When finely powdered, charcoal is more 

 dangerous than when in sticks. Sixty pounds of powdered 

 charcoal is sometimes a large enough quantity to ignite spon- 

 taneously. Lumps of charcoal, if moist, and subjected to a 

 slight drying heat, will ignite." 



Professor C. J. Jackson (United States) reports, " Three 

 times I have set fire to charcoal at temperatures below that of 

 boiling water. My first experiment or observation was acci- 

 dental. I was preparing, while at Bangor, Maine, for a lecture, 

 in which I had occasion to show an artificial volcano. I took 

 a tray filled with gunpowder, and laid it on the stove to dry. 

 I then took a paper of pulverised charcoal, such as is sold by 

 apothecaries for tooth-powder, the charcoal being wrapped in 

 white paper, and placed it on the top of the gunpowder which 

 was being dried upon the stove. Having occasion to go out, 

 I took off the paper of charcoal and laid it upon the table. 

 "When I came back, in twenty minutes, I observed the paper 

 smoking. The charcoal was completely consumed. During 

 all this time the gunpowder remained on the stove unexploded. 

 My next observation was this : While at work in my laboratory 

 I had occasion to use a piece of charcoal for blowpipe experi- 

 ments. I went down into my cellar and brought up a piece 

 of light, fine, round charcoal suited for the purpose. It was 



