204 STORRS AGRICULTURAL EXPERIMENT STATION. 
upright. Their diameter is small in order to provide for the 
minimum passage of heat from the bomb to the water-hold- 
ing cylinder, so that the amount directly communicated to the 
latter shall not be large enough to interfere with the accuracy 
of the determination. We have lately observed, in special 
experiments made for the purpose, that when substances are 
burned in the bomb the lower portion of the latter is but 
slightly warmed. As the pins are decidedly inconvenient in 
many ways, the feasibility of dispensing with them entirely or 
providing a more convenient substitute is under consideration. 
Lining of the bomb.—It is necessary that the inner surface 
of the cylinder and cover be protected from the oxidizing action 
of both the oxygen at the high temperature of the combustion 
and the nitric (nitrous?) acid formed. ‘The most convenient 
protection is a lining of platinum. In the bomb as devised by 
Berthelot the amount of platinum in the lining and in the 
stopper which serves as cover is very large, and at the present 
price of platinum so costly as to put the apparatus beyond the 
reach of most investigators. 
An essential feature of the bomb here described is the use 
of a thin lining of platinum for both cylinder and cover. 
The cover is lined with sheet platinum. In the one pre- 
viously described the lining of the cylinder was a cup made 
of sheet platinum. This was made by rolling a sheet into 
a cylinder of proper size, gold soldering the seam, pressing 
a circular disk into proper’ form for the bottom, and gold 
soldering it to the cylinder. The upper end was stiffened by 
a thicker ring of platinum, and the whole made to fit the 
cylinder. This cup served the purpose most satisfactorily, but, 
as would be expected, the gold-soldered seams showed a weak- 
ness with use, and frequent repairs became necessary. A seam- 
less cup of platinum thus proved desirable, and. experiments 
were instituted by Messrs. Baker & Co., of Newark, N. J., 
who succeeded in spinning from one piece of platinum a cup 
which accurately fits a cylinder of the dimensions above given. 
The corners at the bottom aré rounded for convenience in spin- 
ning and in use. One of the cups thus spun proved some- 
what porous, but Messrs. Baker & Co. have found means for 
avoiding this difficulty. The mechanical skill which has given 
so successful a result seems to us fortunate as it is noteworthy. 


