MISCELLANY. 



"3 



to thirty feet, being penetrated by the 

 frosts of the glacial epoch, and subject to 

 the same laws of action as real glaciers. 



The course of the fragments of differ- 

 ent strata, as shales, quartz-veins, etc., can 

 be traced down the slopes, showing unmis- 

 takably the mode of action; and the distri- 

 bution of bowlders and of gold throughout 

 this drift, though otherwise inexplicable, is 

 readily accounted for by this hypothesis. 



A Note on the Radiometer, by Prof. T. C. 

 Mendenhall, of Columbus, Ohio, explained 

 his method of illuminating this instru- 

 ment for the purpose of projecting an en- 

 larged image of the arms or fans upon a 

 screen. 



The radiometer being suspended ver- 

 tically, a beam of light is reflected upward 

 through it, and made to fall upon a mirror 

 above, which, with the aid of a projecting 

 lens, produces the image of the movable 

 fans upon the screen. As the beam of 

 light produces no motion when striking 

 these fans edgewise, the most delicate ex- 

 periments can be made, and their effects 

 seen, without any disturbance caused by the 

 light used in projection. 



On cooling the Air of Bnildings dar- 

 ing Hot Weather, by Prof. Simon New- 

 comb, was a valuable paper, which was 

 practical enough to satisfy those who de- 

 mand that the value of all scientific labors 

 shall be tried by the test of utility. The 

 failure of the many plans which have been 

 suggested for cooling buildings in summer 

 has arisen from overlooking the fact that 

 the human body is a " wet-bulb thermome- 

 ter," and that the air needs not alone to 

 be cooled, but to be brought to a condition 

 which will allow speedy evaporation, and 

 that, therefore, contrivances for simply 

 cooling the air have not resulted in a de- 

 gree of comfort at all commensurate with 

 their trouble and expense. We have but 

 to remember the discomfort of a moist, 

 " muggy " day, even when the mercury 

 marks a moderately low temperature, to 

 see that the air needs not only to be cooled, 

 but to be dried. It will not answer to dry 

 the air by chemical absorption, as by sul- 

 phuric acid or lime, on account of the heat 

 of the chemical union. 



vol. x. 8 



The only satisfactory way to remove 

 the moisture is by condensation and depo- 

 sition, and for the purpose of doing this 

 effectually and economically Prof. New- 

 comb suggests an apparatus. He proposes, 

 by passing the ordinary air of a summer 

 day through an ice-chest, to reduce it to a 

 point far below the dew-point or, say, 35 

 Fahr. Thence it should be passed through 

 a very large tin tube on its way to the out- 

 side air. Inclosing this cold-air tube, is to 

 be another, still larger, through which warm 

 air from the apartments is to be forced ; 

 the two streams passing in opposite direc- 

 tions, the readily conducting substance of 

 the tubes facilitating the vigorous efforts 

 of the hot and cold currents to reach an 

 equilibrium, the moisture being, meantime, 

 rapidly deposited on the large condensing 

 surfaces of the tubes. The outlets of the 

 tubes are to be together, and the resulting 

 mixture would be a volume of dry air at a 

 comparatively low temperature. If, for 

 example, the air in passing through the ice- 

 box was reduced to 35, while the air ad- 

 mitted to the outer tubes was at 95, the 

 result would be a mixture of dry air at 

 about 70, which, if mingled in considerable 

 volume with the ordinary air of a room on 

 a hot summer day, would be greatly condu- 

 cive to comfort. The greatest value of 

 Prof. Newcomb's suggestion is in utilizing 

 the cold air on its passage for the purpose 

 of condensing moisture. As to the quan- 

 tity of ice needed to cool a given space, 

 Prof. Newcomb was not prepared to give 

 any exact figures., although he had made 

 some estimates. He thought, however, 

 that, at the price of ice in Washington, the 

 cost of cooling the Capitol would be forty 

 or fifty dollars per day. 



Some New Points regarding the Tongue 

 of the Picus Viridis (green woodpecker) 

 was the title of a brief paper by Dr. Joshua 

 Lindahl, of Sweden, in which he pointed 

 out some errors in the common descrip- 

 tions of the remarkable extension of the 

 hyoid bones over the skull, which char- 

 acterizes the woodpecker family. Having 

 occasion to dissect the head of the green 

 woodpecker of Sweden, he observed that 

 the elongations of the posterior cornua of 

 the hyoids, instead of passing symmetrical- 



