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SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 72 



cook, wash, cut firewood from the small oak bushes and dwarf yuccas 

 about, and repair or alter the building or the apparatus as occasion 

 requires, besides carrying on the solar investigation. 



During the occupation of Mount Wilson in 1920, many pieces of 

 research were successfully carried through by Messrs. Abbot and 

 Aldrich besides the measurements of solar variation. One of the 

 most interesting was the perfecting of the solar cooker begun several 

 years ago. A parabolic cylindrical mirror with polished aluminum 

 surface of about 100 square feet focuses the sun's rays upon a 

 blackened tube filled with mineral oil communicating to an iron 



Fig. 26. — Solar cooker on Mt. Wilson. 



reservoir of oil in which are two baking ovens. A continuous circu- 

 lation of the heated oil keeps the ovens hot enough to perform all 

 cooking operations except frying. Excellent bread, meat dishes, 

 vegetables, cereals, canned fruits and vegetables and preserves were 

 cooked there by Mrs. Abbot, who had charge of this part of the 

 experiments and who was much envied for her cool kitchen and novel 

 appliance by the ladies of the mountain. This solar cooker was con- 

 structed on Dr. Abbot's plans largely at the cost of grants from the 

 American Academy of Arts and Sciences in Boston, and the National 

 Academy of Sciences. It has proved successful, but must be regarded 



