
IMPROVED FORMS OF BOMB CALORIMETER. 199 
IMPROVED FORMS OF BOMB CALORIMETER AND 
ACCESSORY APPARATUS. 

BaeWe OL WALHRUAND O, S. BLAKHSEHE: 
——_#+¢e——_. 
A previous Report of this Station gave an account of a bomb 
calorimeter which had been found useful for determining the 
heats of combustion of organic substances including foods and 
feeding stuffs.* In the experiments carried on by this Station 
on the food and nutrition of animals and men, this apparatus 
has been in constant use for several years and the experience 
has led to a number of improvements in the apparatus, acces- 
sories, and manipulation. The need of such an apparatus is 
coming to be more and more widely felt. A number of labora- 
tories are now using it, and the inquiries regarding it are con- 
stantly coming to us from investigators in this country and in 

* A New Form of Bomb Calorimeter, by W. O. Atwater and Chas. D. Woods. 
Report of the Storrs (Conn.) Experiment Station for 1894, p. 135. 
The article describes briefly the bomb of Berthelot, and explains the only difficulty 
in the way of its use, namely, the high cost due to the large amount of platinum used 
in the lining and cover. The price of the bomb and accessories in 1893 was about 
$1,200. The following statements are taken from the article: 
“Various modifications of Berthelot’s apparatus have been devised especially to 
‘‘ obviate the difficulty of expensive lining. Mahler uses a bomb of forged steel with 
“enamel lining. (Compt. rend., 113, 774, and 862, and Génie Civile, Jan. 23, 1892, 
‘“p, 198. See also Zeitsch. f. anal. Chem., 1893, 79, and Berthelot, Calorimétrie Chimique, 
“733,) Thecylinder issomewhat narrowed at the top and the cover is screwed directly 
“upon it, the junction being made tight by a washer or gasket of lead. The enamel 
‘‘is easily put on or replaced, and it is stated that a single coating has been used for 
‘*300 combustions without injury. It has been frequently found, however, that the 
‘“ enamel scales off in constant use. The form described by Mahler has an internal 
‘‘ capacity of 600 cubic centimeters, or nearly double that of Berthelot’s bomb, as above 
‘** described.”’ 
‘““ Prof. Hempel of Dresden uses, for determination of heats of combustion of coal, 
‘a simple bomb of steel without lining. The principle, like that of Mahler’s form, is 
“the same as that of Berthelot. The closure is by a ‘head piece’ which screws into 
“the neck of the bomb. It suffices very well for technical purposes, but is not recom- 
‘‘ mended for scientific use. (Hempel, Gasanlytische Methoden, 1890, 355, and Eng- 
‘‘ lish translation, Methods of Gas Analysis, 1892, p. 359.)”” ‘ ; 
“ In accordance with suggestions by one of us (W. O. A.) during a sojourn in Dres- 
‘den, Prof. Hempel most kindly had a bomb made by the mechanicians who make 
“the bombs of his devising just referred to, and lined, by Heraeus of Hanau, witha 
“thin sheet of platinum. Through Prof. Hempel’s painstaking care, added to his 
“inventive skill and his peculiarly thorough familiarity with the whole subject, an 
‘apparatus was obtained which has proved most efficient. The principle is the same 
“asin Berthelot’s form: but whereas the cover of Berthelot’s fits into the cylinder in 
‘the manner of a very wide stopper, the cover in this, as in Mahler’s, rests directly 
‘upon the upper edge of the cylinder, a projection of the latter fitting into a groove 
“of the former. A washer of lead is set in the groove of the cover, the latter 1s held 
‘tightly to the cylinder by a screw cap or collar and thus perfect closure is easily 
rsecuted,”’ 
Experience since that article was written has led to further improvements in the 
bomb and accessory apparatus. A number of the improvements in the bomb, and 
especially the new forms of accessory apparatus, have been devised by Mr. Blakeslee, 
Mechanician of Wesleyan University, by whom the whole apparatus is now made. 
Valuable suggestions have been made by Prof, C. D. Woods. Wi Ona: 
i, 
, é 
ee roe / 
