The University of New Hampshire [Bulletin 338 



RECORDING INSTRUMENTS USED 



Instruments for recording humidity and temperature were placed 

 in the plot liouse and Pen 16, on December 3, 1938 and maintained in 

 these positions throughout the course of the experiment. Each con- 

 sisted of a liquid type recording thermometer and a horse hair record- 

 ing hygrometer, installed on shelves hung from the ceiling, the plot 

 house recorder being about 4^' off the floor and the poultry pen 

 instrument about 5' from the floor. A continuous automatic record 

 of humidity (in terms of percent moisture) and of temperature (in 

 degrees Fahrenheit) was kept by these instruments. 



Two wet-dry bulb recording instruments with weekly charts were 

 operated for part of the time in Pens 1 and 2. 



LITTER SAMPLING 



To determine the moisture content of litters both in plot house 

 and poultry pens, samples of these litters were taken weekly and a 

 record of their moisture content was maintained throughout the test 

 period. The sampling in plots was done by taking 3 or 4 scoops of 

 the litter material from each plot. In the poultry pens, sampling 

 meant that six scoops of litter were taken from the floor, one from 

 each corner of the house, one from the rear center of the pen under 

 the dropping board and the other within one foot of the waterer. These 

 scoops were mixed thoroughly in a bushel basket and a sample was 

 transferred to a quart jar, loosely poured in until a weight placed in 

 the neck of the jar showed it full. 



DETERMINATION OF MOISTURE CONTENT OF SAMPLES 



Samples were tightly sealed with a jar rubber and screw cap to 

 prevent loss of moisture between the time of sampling and the drying 

 test. 



The drier was a large metal cabinet heated by a coil of steam 

 pipes. Ventilation was provided by a 54 h-P- exhaust fan connected 

 m the ventilating shaft. The fan and shaft also aided in carrying oft' 

 odors from the samples during drying. The fan moved air from the 

 drier at a rate of 860cu. ft. per minute, providing three air changes per 

 minute. 



The temperature of the cabinet interior was maintained between 

 180° and 190° F. During the weighing procedure, when doors were 

 being opened and closed frequently, the temperature would drop to 

 130° or 140° F. 



Each litter sample was removed from the jar and placed in an 

 open pie pan, weighed and then placed on a wire screen shelf in the 

 drier. Weights of the samples were taken at 72, 138 and 172 hours 

 following their entrance into the cabinet. The final 172-hour weigh- 

 ing was a check on the 132-hour weight, but as full evaporation of 

 moisture was accomplished at the 132-hour period, calculations are 

 on this basis. 



The grams of moisture evaporated was found by subtracting the 



