142 STORRS AGRICULTURAL EXPERIMENT STATION. 
In Berthelot’s bomb, as I am informed by the maker, it is 
found necessary to use a large amount of platinum in the 
stopper to make it firm, so that although the platinum lining of 
the cylinder below the neck is only about one-half millimeter 
thick, over a kilogram of platinum is required for the whole. 
This simple substitution of a platinum-lined’ steel cover saves 
the ‘larger part of the, platinum: ‘Che cost of: the) bomipma 
Dresden, with accessory apparatus, including vise-grip and 
lever for screwing on the collar, a cylinder for compressed 
oxygen, fittings, manometer and a screw press* for making 
hard pellets of the substance to be burned, was less than $220. 
The apparatus has been in use in our laboratory for more than 
two years, all the combustions of which the results are given 
in the present Report were made with it, and we have found it 
very satisfactory. 
The bomb as just described might be recommended for general 
use in place of the very expensive form devised by Berthelot. 
Our experience has, however, suggested some alterations, and 
the attempt is being made, to develop an apparatus which, with- 
out sacrifice of accuracy and reliability, will be durable, convenient 
and capable of being made at a cost which will bring it within 
the reach of ordinary laboratories. ‘The efforts in this direction ~ 
are being materially aided by the U.S. Department of Agricul- 
ture. The results thus far are very encouraging, but we are not 
yet certain what kind of metal will ultimately prove best for the 
bomb or for the lining, and there are numerous details of con- 
struction and manipulation which still need to be worked out and 
tested. 
The main objective point at present is to diminish the cost of 
the lining. Whether this will be best accomplished by a cheaper 
lining of platinum, or by a lining of another metal, or by using a 
less corrosive metal than steel for the bomb and thus avoiding 
the lining altogether, remains to be seen. But there is no doubt 
as to the feasibility of making an excellent bomb of steel with a 
thin platinum lining. 
Two steel bombs have been made by the Pratt & Whitney 
Co. of Hartford, Conn., and to whose personal interest in the 
matter, with that of Mr. G. M. Bond of their establishment, 
especial thanks are due. ‘Their facilities for making such ap- 
paratus are very unusual in respect to mechanical appliances, 

* As used by Hempel, loc. cit. 


