CORRESF ONDENCE, 



233 



CORRESPONDENCE. 



CURIOUS MOUNDS IN CALIFORNIA. 



To the Editor of the Popular Science Monthly. 



OX the stage-road from Mariposa to 

 Merced — a portion of the Yosemite 

 Valley route — for a distance of twenty miles, 

 the surface of the ground, as far as the eye 

 can see, is singularly characterized. 



Circular elevations, like mammse, about 

 two feet high and twenty feet in diameter, 

 are divided by shallow ditches, or swales, 

 about ten feet wide. These mounds are sur- 

 prisingly symmetrical, and occupy the whole 

 surface. Where the rising ground meets the 

 sky, the outline is regularly scalloped. The 

 freshets have in some places cut through to 

 the depth of three feet, leaving the vertical 

 section exposed to view. 



All the stones contained in the mounds 

 are rounded, and in size are from half an 

 inch to four inches iu diameter. None 

 larger were seen. The bottoms of the dry 

 water-courses are paved with these round 

 stones to a considerable depth, the largest 

 on top. For six inches in depth of the sur- 

 face of the mounds the soil is free of stones ; 

 below that, the stones are distributed with- 

 out much regard to size, the spectator being 

 impressed with the apparent fact that the 

 larger ones are nearer the surface. 



Rising ground equally with level surface 

 is covered by these maramfe. In rare cases 

 are two mounds thrown together, so as to 

 interfere with the generally symmetrical ar- 

 rangement. A plausible explanation of the 

 cause of this phenomenon occurred to me : 

 After the surface had been smoothed, and 

 the large elevations rounded, by the moving 

 glacier, the ice-mass became stationary from 

 diminished thickness. The larger stones on 

 the surface would melt through, forming 

 funnel-shaped cavities, into which the water 

 on the surface of the glacier would pour 

 and run out at the bottom, leaving the ac- 

 companying dirt and gravel in a heap. But 

 this theory requires that the stones causing 

 the funnel-shaped cavities should be dis- 

 tributed on the surface of the glacier at uni- 

 form distances of twenty-five feet from each 

 other, which supposition is inadmissible. 



I am constrained to ask for a proper in- 

 terpretation of the origin of this notable ar- 

 rangement. S. H. Mead. 

 Davenport, Iowa, July 11, 1878. 



MUTILATIONS AND IIEEEDITT. 



To tM Editor of the Popular Science Monthly. 



In January, 1875, \ bad a tortoise- 

 shell cat that lost her left fore-paw, as I 



suppose, in a steel trap. About ten weeks 

 after this accident she had a litter of kit- 

 tens, and, one being a tortoise-shell, it was 

 saved. The first cat lived about a year. 

 In addition to her limping around on three 

 feet, she had a peculiar habit of holding up 

 the lame foot against her breast, as though 

 she was nursing it, and would frequently 

 come and touch me with it, looking up at 

 me with a pitiful expression on her face. 

 Last spring I obtained a tortoise-shell kit- 

 ten, a granddaughter of the lame one and a 

 daughter of the cat that was born after the 

 foot was hurt. Now, this kitten has the 

 habit of standing almost constantly on three 

 feet, holding the left one from the ground 

 (sometimes, but not often, she holds up the 

 right one), and she frequently holds it to 

 her breast, as though she were nursing it, 

 in exact imitation of her grandmother, the 

 lame one. She also has the habit of com- 

 ing up and touching me with her paw, put- 

 ting on the pitiful expression of counte- 

 nance that was observed on the face of her 

 ancestor. J. D. A. 



Ceomwell, Connecticut, October 21, 1878. 



DOES THE MICROPHONE MAGNIFY 

 SOUND ? 



To the Editor of the Poptdar Science Monthly. 



Sir : The account of the actual accom- 

 plishments of the microphone, in the way 

 of magnifying faint sounds, as communi- 

 cated to the Royal Society in May last, was 

 so astonishing that every one was led to 

 believe a scientific discovery of immense 

 value had been given to the world, con- 

 taining in embryo practical appUcations of 

 unbounded extent. 



Not the least remarkable feature of this 

 discovery was the extreme simplicity of 

 the apparatus, thereby enabling the merest 

 dilettante to repeat the experiments detailed 

 in Prof Hughes's paper ; and I doubt not 

 that a number of experimenters have ex- 

 pended a good deal of time and patience in 

 endeavoring to develop these embryonic pos- 

 sibilities. 



It is for the purpose of eliciting the 

 candid opinion of such workers, who may 

 have been more successful than I, that I 

 am induced, through the medium of your 

 valuable journal (while avoiding theoretical 

 considerations which have been exhaustively 

 discussed), to state very briefly the conclu- 

 sions that I have arrived at after a careful in- 

 vestigation with microphones of varied form : 



1. The micropkone docs not magnify 



