May, 1929] SIMPLIFIED TECHNIQITE FOR MEASURING ENERGY 



11 



Since the respiration chamber in use at Durham was first described,^ 

 it has been materially improved by the addition of facilities for feeding, 

 watering, and for the separate collection of feces and urine during an 

 experiment. A simple device has been added to indicate when the animal 



Figure 3 — Schematic outline of respiration chamber for cows and steers, arul device for sepa- 

 rate collection of urine and feces 



B, blower conducting fresh, outdoor air into space between inner and outer doors of 

 chamber; a, hne and pulley arrangement for recording when animal changes body posi- 

 tion; e, position of blower, on the outside of chamber wall, which removes air from the 

 chamber (see also B, Fig. 5); m, movable platform supported by spring, h, and chain, j, 

 and attached to pneumograph, p, which communicates changes in air pressure due to 

 movement of animal through tubing, k, to a tambour pointer and kymograph drum out- 

 side chamber; d, water trough connecting with outside water tank, W; b, balance 

 for weighing of water; F, feed box; D, movable or sliding shutter for use in sealing off 

 chamber from outside feed chute; H, hand crank controlhng movement of D and F; M, 

 manometer to indicate air pressure in respiration chamber; f, crank handle for moving feed 

 box; S, S, air sealed sheet metal container (housing device) for separate collection of feces 

 and urine from cows; C, chute leading down from grid. For further details of frame construc- 

 tion and details of apparatus for ventilating the chamber, for measuring the amount of 

 ventilation, and for absorption of carbon dioxide and water, see Bull. 16 of this Station. 



changes position from standing to lying, or vice versa, so that separate 

 determinations can be made of energy expended for these body positions. 

 A few minor improvements have also been made in the interior fitting 

 and finish of stall accommodations to make the conditions for the animal 



1 Benedict, F. G., W. E. Collins, Marv F. Hendrv and Alice Johnson. N. H. Sta. Tech. 

 Bull. No. 16, 1920; Benedict, F. G. and E. G. Ritzman, Carnegie Inst. Wash. Pub. Nos. 

 324 (1923) and 377 (1927). 



