224 EXPLORATIONS ACROSS THE GREAT BASIN OF UTAH. 



Mr. Schott's classification of Dr. Kane's 17 daily observations is as follows: 



Daily range less than 1° «. 



Daily range between 1° and 2° 6 



Daily range between 3° and 4° 3 



Daily range between 4° and 5° 3 



Daily range greater tban 5° -' 



The observations we made were quite numerous, but as they are filed in the Bu- 

 reau of Topographical Engineers for reference, it is thought best not to incumber the 

 report with them, but only to subjoin a set of each as a specimen of the rest. The 

 results, however, are presented below in a tabulated form, and also graphically on the 

 small charts of the declination and inclination of the needle herewith (see Plate). 

 These charts, I would remark, so far as the data shown across the continent, from 

 Fort Smith, Ark., to the canon of Chelly, in New Mexico, and from Fort Leavenworth 

 to Genoa, in Carson Valley, are concerned, are an extension by me of the latest 

 charts on this subject from the United States Coast Survey. The Superintendent of 

 the Coast Survey, Prof. A. D. Bache, has kindly furnished me with their latest mag- 

 netic charts, and it is a gratification to me, by my explorations in 1849, from Fort 

 Smith, via Santa Fe, to the canon of Chelly, and by my recent expedition from Fort 

 Leavenworth to Genoa, to be thus able to supply a great deal of magnetic data, which 

 will extend our knowledge of this element over a larger area of our country, and 

 make these charts still more useful. 



In addition to the above I would make the following remarks in relation to the 

 electric condition of the atmosphere in the Great Basin. I have noticed that my flan- 

 nel, when cast off at night before retiring to rest, would evince, by a crackling sound, 

 that it was highly charged. This would frequently be the case in combing one's whis- 

 kers, or handling a bear-skin. All this doubtless points to the very dry state, and, 

 therefore, non-conducting power, of the air, and the non-escape of the electric fluid 

 from terrestrial bodies except by the proximity of others. 



I would also extract the following from my report of my explorations in the fall 

 of 1858, in Utah, as bearing on this subject: 



"It is astonishing to notice the effect of the whirls and gusts of wind upon the 

 magnetic needle, or, more properly speaking, to see the action of the magnetic needle 

 at the time these whirls and gusts are in development, The fact of these disturbances 

 appearing together does not necessarily point to the same cause producing both, but 

 makes it strongly probable that the cause is one and the same in both cases. The 

 needle, whenever these gusts and whirls are in exhibition, would stick either to the 

 north or south end of the bottom of the box, and no change of position could make it 

 stir. Sometimes the effect would be to disturb the needle very much, and to make it 

 point indifferently to any point of the compass. When, however, the gusts would 

 cease, the needle would act normally as usual."* 



A somewhat similar phenomenon exhibited itself subsequently at Camp Floyd, in 

 March, 1850, when, however, the weather was fair, though there was some little wind. 

 I was verifying some observations for magnetic declination, by placing a surveyor's 

 compass, on the meridian, immediately over the transit station, with the intention of 



* See Senate Ex. Doe., No. 40, 35th Cong., 2d session, p. 28. 



