58 



SCIENCE. 



[Vol. It., No. 23. 



INTELLiaENCE FROM AMERICAN SCIENTIFIC STATIONS. 



GOVERNMENT ORGANIZATIONS. 



Naval tnreau of ordnance, 



Experiments at Annapolis. — By direction of the 

 Naval bureau of ordnance, experiments witli the 

 six-inch steel gun were resumed at the experimental 

 battery recently, the chief object being to develop 

 and encourage the home manufacture of steel pro- 

 jectiles. Steel projectiles manufactured by the Mid- 

 vale steel company near Philadelphia, having different 

 physical characteristics as to toughness, extensibility, 

 etc., were fired at a target consisting of two mild steel 

 five-inch plates strongly bolted together, and baclced 

 with twenty inches of live-oak. The first and the 

 second shots brol^e up; the third pierced the plates, 

 and was stopped by the bacliing ; while the fourth 

 perforated target and baclving, and buried itself in a 

 mound of earth beyond the target. This projectile 

 had an initial velocity of 1,983 feet, and weighed 75 

 pounds. The charge of powder was 32 pounds, and 

 the striliing energy per inch of shot's circumference 

 was 108 foot-tons. The results indicate that there 

 will be no serious difficulty in procuring the proper 

 material for armor-piercing shells in this coun- 

 try. 



A somewhat remarkable result was obtained with 

 a projectile weighing 52 pounds, and a charge of 33 

 pounds of powder. The muzzle velocity obtained 

 was 2,323 feet per second, with a pressure of about 13 

 tons. The ratio of charge to projectile was adopted 

 as being nearly that which will be used in the 

 new ten-inch guns designed by Commodore Sicard. 

 These guns will be manufactured at the Washington 

 navy-yard, and are intended for the batteries of the 

 four double-turreted monitors. 



It does not necessarily follow that results equally 

 favorable will be obtained with the ten-inch gun, 

 since the masses of 'both charge and projectile will 

 be greatly increased. The pressures will doubtless be 

 higher; but these guns will be sufficiently strong to 

 "withstand a working pressure of more than 25 tons 

 to the square inch. The indications, however, are, 

 on the whole, extremely favorable to the success of 

 the ten-inch gun. 



This experiment is likewise interesting when com- 

 pared with the record of a six-inch gun constructed 

 by Sir William Armstrong, in which, with an 80- 

 pound projectile and a charge of 55 pounds of pow- 

 der, a muzzle velocity of 2,297 feet was reached 

 with a pressure of 21 tons. In the latter case the 

 ratio of charge to projectile is 11 : 16, whereas in the 

 former case the ratio is 11 : 17J-. It is to be regretted 

 that the size of the chamber of this experimental 

 gun does not permit the employment of a larger 

 charge of powder. 



Two six-inch guns, representing the types proposed 

 for the broadside batteries of the new steel cruisers, 

 are now in process of construction at the Wash- 

 ington navy-yard, and will be ready for testing in 

 August. — J. M. E. 



U. 3. magnetic observatory at Los Angeles, Cal.^ 



Magnetic observations. — There is at present but 

 one self-registering magnetic observatory within the 

 limits of the United States. That observatory is 

 located in Los Angeles, Cal. ; and the object of the 

 present article is to present a brief description of 

 the observatory and its work, together with a short 

 account of its origin. 



Continuous series of magnetic observations, cover- 

 ing longer or shorter periods, have been made at 

 several stations in North America ; but, with two ex- 

 ceptions, they have all been made on the eastern side 

 of tlie continent. We have a series of observations 

 of five years (1840-45) at Girard college, Philadel- 

 phia, by A. D. Bache; six years' observations at Key 

 West, Fla. (1860-66), by the U. S. coast-survey; and 

 a long series, still continuing, at Toronto, Canada 

 (1841-83). We have, further, a series of nearly five 

 years of photographic records taken at Madison, 

 Wis., by the XT. S. coast and geodetic survey. 



On the western coast the only continuous series of 

 magnetic observations we have, were made by the 

 Russian government at Sitka at the magnetic and 

 meteorological observatory established in March, 1842, 

 and maintained until the cession of Alaska to the 

 United States in October, 1867; and the series of 

 hourly observations at Point Barrow in 1852-54 by 

 Capt. Maguire, E.N. Up to the present time, a great 

 part of these observations have remained undigested 

 and undiscussed. 



It was therefore contemplated by the coast-survey, 

 many years ago, to obtain a continuous series of mag- 

 netic records from some station on the western coast 

 of the United States ; and, with this end in view, an 

 Adie magnetograph of the latest and most approved 

 pattern was purchased in 1860. The outbreak of the 

 war, however, prevented the carrying-out of this 

 plan. 



The instruments remained packed until 1878, when 

 a favorable time seemed to have arrived to put it 

 to use. Assistant C. A. Schott, aided by Mr. Suess, 

 then set it up for trial in the basement of the coast- 

 survey office in Washington. Some minor defects 

 of construction were remedied, and the magneto- 

 graph set to work in January, 1879. It was kept 

 going for about two weeks on trial, and found to 

 perform satisfactorily. During this time, it was in- 

 spected by Superintendent Patterson, and its work- 

 ings observed by various members of the survey. At 

 the close of this trial it was packed up for shipment 

 to some station in California. 



It was found, iiowever, that more money would be 

 required to run the instrument than could be then 

 set apart for this work, and it therefore remained 

 in the coast-survey office. 



In response to the invitation of the International 

 polar conference, our government consented, in 1881, 



1 Coramunicated, with permission of the superintendent of 

 the U. S. coast and geodelic survey, by Marcus Baker, acting 

 assistant in charge of the observatory. 



