F. E. Nipher— New form of Lantern Galvanometer. Ill 



depth of from 100 to 500 feet in solid frozen soil and ice ribs. 

 I am inclined to believe that the glacial condition of McClellan 

 Mountain is due to local causes. Prominent among these would 

 be the loose nature of the soil and deep rockj debris of the moun- 

 tain, and the slow percolation of water exposed to excessive 

 evaporation that is promoted and quickened bj continued gales 

 from the north and northwest that strike against the precipitous 

 face of the mountain range in that direction. The opposite slope, 

 on the contrary, which shows the abnormally high timber line, 

 faces a Pass (Argentine Pass) 13,100 feet in height, which gives 

 a way perfectly unobstructed for south-southwest winds. These 

 prevail frequently in winter and spring, and are invariably tem- 

 perate or even warm, and thus to their influence may be due the 

 milder and more propitious character of this locality. In Col- 

 orado Territory it has been remarked that in our mountains, even 

 in January, a southwest wind is invariably genial and warm ; in 

 two hours I have known a southwest wind to raise the thermom- 

 eter from 13° below zero to 47^ above. This abrupt change, how- 

 ever, is disastrous to tree growth, and destroys the quaking Asp, 

 Cedar, and even Pines in more exposed locahties; while the 

 Cherry, Box Elder and the bitter Cottonwood {Popuhis angulatd) 

 have perished in the ensuing spring in our lower valleys and 

 on the foot-hills. 



I have presented this subject in order to secure for it further 

 elucidation and discussion. The facts are of no little interest, 

 since they conflict with accepted views as to the limits of 

 growth of plant, and the influence of altitude on climate. 



Art. X. — On a New Form of Lantern Galvanometer; by 

 Francis E. Nipher, Professor of Physics in Washington 

 University.* 



In the September number of this Journal, Prof. Barker has 

 described a lantern galvanometer, which appears to possess 

 many advantages over any heretofore described, and which is 

 evidently a valuable addition to the apparatus of the public 



While meditating the construction of this instrument, the 

 galvanometer now to be described was devised. A vertical 

 section is shown in Fig. 1. 



A square box (Y, Y), open at the top and bottom, is pierced 



on opposite sides to admit the wooden rods (6). To the inner 



extremities of these rods are attached coils (R), of covered cop- 



* Read before the St. Louis Academy of Science, Oct 18, 1875, 



