1 SO ANNUAL KECOHD OF SCIENCE AND INDUSTRY. 



eastern slopes of the Ancles and on the pampas are of shorter 

 duration than on the west side. The lower horizontal sur- 

 face of the clouds, which is at an altitude of 1500 or 2000 

 meters, sometimes extends from the coast eastward to far 

 beyond the Andes. The greatest thunder-storms in Chili 

 last three or four days, but the electric discharges all occur 

 in the first hour. 



Carl AVeyprecht has published the "Magnetic and Aurora 

 Observations of the Austro-Hungarian Arctic Expedition of 

 1872 to 1S74," with which he also gives an excellent analysis 

 and resume of our knowledge on the subject. Among other 

 things, he strongly inclines to the opinion that the auroral 

 light belongs to the lower portion of the atmosphere. He 

 fails to establish any connection between the aurora and the 

 weather. He concludes that the zone of maximum frequency 

 moves northward during the winter, and again southward 

 during the spring. 



Thalen has a memoir on Exploitation for Iron Ore by 

 Means of the Magnetic Needle. He gives full and strictly 

 accurate methods, and his formula? may possibly be applica- 

 ble to the search for the seat of the disturbances that accom- 

 pany auroras. 



An elaborate paper on the Protection of Buildings from 

 Lightning, by Dr. Mann, is republished, with additional notes, 

 in the sixth volume of the "Professional Papers on Indian 

 Eno-ineerin2;." 



The American Academy of Sciences of Boston has instituted 

 an inquiry with reference to the general phenomena of light- 

 ning, and, among other things, has requested the Chief Signal 

 Officer of the Army to collect, as far as possible, all notes and 

 observations upon accidents caused by lightning. All who 

 may read this note are cordially invited to record such facts 

 as mav come to their knowledge. 



The Proper Method of Protecting Buildings by Lightning- 

 rods is discussed, in a fifth note, by Melsens, in the Brussels 

 Bulletin, 1878, p. 43. lie gives an analysis of the conditions 

 necessary to insure efficacy, and discusses the constructions 

 published by the French Commission. 



According to Mr. Symons, both Mishel, Secretary of the 

 French Commission on Lightning-rods, and Jarriant, a large 

 dealer in lightning-rods adopt as the area protected from 



