22 UNIV. OF N. H. AGR. EXPERIMENT STATION [liulletill 250 



bination with the electric dairy cold storage; the others were individual 

 household refrigerators. The latter type may be further divided into 

 three divisions — the modern commercially built single cabinet unit, the 

 commercially built refrigerator converted to electric refrigeration, and 

 the home-made refrigerator converted to electric operation. 



Comparisons of costs with the ice method of refrigeration were made. 

 Investment in equipment was higher for the electric method, being $370 

 compared to $282 for ice equipment. The total fixed charges were $12.15 

 for ice and $18.20 for the electrical method. The house and dairy needs 

 on one farm were met with an expenditure of $766.50 for a single combina- 

 tion unit. Compared with $885.80 and $889.34 on two other farms for 

 separate sets of equipment for house and dairy this represents a saving of 

 $120 and $225 in favor of combination equipments. 



In the amount of current consumed variations between .0016 kwhs. and 

 008 kwhs. per cubic foot of total box capacity per hour occurred. The 

 locations of the compressor and refrigerator were found to have an im- 

 portant influence on cost of operation. The maximum consumption for 

 the year was 514 kwhs., and the minimum consumption was 151 kwhs. ; the 

 average for all machines being 385. The combination method was found 

 to require 30 per cent less current for the year than the separate unit 

 method. 



Current consumption on the five standard type refrigerators averaged 

 41 kwhs. per month. The average maximum consumption was 67 kwhs., 

 and the average minimum consumption, 100 kwhs. Compresser units 

 operated 19 per cent of the time. 



Total annual costs for using ice had previously averaged $41.63 per 

 year, a daily average of 21 cents. 



Details of the experiment are given in Bulletin 244, "Electric House- 

 hold Refrigeration." {Miscellaneous Income.) 



CERTIFICATION OF POULTRY 



In its second season the demand for service in poultry certification in- 

 creased 80 per cent. In the season of 1928-29, fifty-one poultry growers 

 secured the aid of H. O. Stuart in selecting breeding stock from 39,823 

 birds. Only accredited flocks are given certification. The purpose of 

 the work is to separate the hens into three classes depending on their 

 ability to produce chicks having the qualities needed for high egg produc- 

 tion. A charge of three cents a bird is made to cover partly the expense 

 of this specialized poultry work. 



Birds of satisfactory production qualities and color which are free from 

 evident heritable disqualifications are certified and placed in Class I. 

 Class II contains birds desirable for egg production purposes. These 

 birds are off color, have one or more disqualifications, or have poorer 

 production ability. Into Class III are placed cull birds which are unfit 

 for economical egg production or breeding purposes. {Miscellaneous 

 Income.) 



SOIL FERTILITY STUDIES 



Experiments in soil fertility, now entering their sixth year, are being 

 conducted on carefully selected sites representative of New Hampshire 

 soils. Five series of investigations, which are being supervised by F. S. 



