l28 



THE MINTS OF THE UNITED STATES. 



[1855. 



This attenuated mist, rendered luminous by the transmission 

 of eleotrieitj, ought to .ippear under a regular f'yrni, like an 

 illuuiiuatod surface of grentor or less extent, and more or less 

 broken. It should spread outward from the poles, forming as 

 a first appearance the auroral bank like a veil in the north. 

 The tenuity of this veil is such that the stars may be seen 

 through it, as has been remarked by all observers. MM. 

 Bixio and Barral, in the balloon ascension which they recently 

 made, suddenly found themselves — although the sky was quite 

 serene and the atmosphere without a cloud — in the midst of a 

 veil or mist, which was perfectly transparent, consisting of a 

 multitude of small icy needles so fine that they were hardly visi- 

 ble. Such are the needles which become luminous by the 

 passage of the electricity, which determine the formation of 

 halos as has been rigorously demonstrated, and produce by 

 condensation the aqueous vapors in their passage through the 

 air towards the earth, the fall of snow or rain, or sometimes 

 under peculiar circumstances, hail. 



Now if we inquire what should pass in the portion of the 

 luminous mist nearer to the earth's surface, we shall conclude 

 that the vicinity of the magnetic pole must exert a decided 

 influence on this electrised matter, — for it is in fact a true 

 mobile conductor traversed by an electric current. 



In order to obtain a correct idea of this action, I have 

 endeavored to imitate artificially the process of nature, and 

 with this view, I contrived the following experiment. 



Into a glass globe, 30 to 40 centimeters in diameter, I in- 

 troduced through one of its two opposite tubulures, a piece of 

 soft iron wire, about 2 centimeters in diameter, making it to 

 terminate at the inner end very near the centre of the globe, 

 while the other end was exposed out of the globe. The wire 

 was covered through its whole length, excepting its extremities, 

 by a very thick insulating bed formed first of shell-lac, then 

 with a glass tube covered itself with shell-lac, then with a 

 second tube of glass and finally with a bed of carefully applied 

 wax. The insulating layer in all was a centimeter thick, giv- 

 ing 4 centimeters for the thickness of the bar thus covered. 

 Within the globe, a ring of copper surrounded the bar and its 

 insulating bed, at the part most distant from the tubulure. 

 This ring was arranged to be put in communication with a 

 source of electricity exterior to that of the bar by means of a 

 metallic wire insulated with care which passed through the 

 tubulure and ended without in a hook. A stopcock attached to 

 the other tubulure of the globe, was arranged for obtaining a 

 vacuum. When the air within is sufficiently rarified, the hook 

 is connected with the conductor of an electric machine, and the 

 outer extremity of the bar of iron with the soil; by this means 

 the electricity forms within the globe a luminous sheaf, more 

 or less irregular, which passes from the ring, and terminates at 

 the inner extremity of the soft iron. But immediately on 

 placing the outer extremity of the soft iron on the pole of an 

 electro-magnet, the electric light takes a wholly different 

 aspect. Instead of proceeding indifferently from different 

 points of the upper surface of the cylinder of iron, it proceeds 

 from all points in the circumference of this surface, so as to 

 form around it a continuous luminous ring. This is not all : 

 this ring has a movement of rotation around the magnetized 

 cylinder, sometimes in one direction and sometimes in the 

 other, according to the direction of the electric current, and 

 the nature of the magnetization. Finally, jets of brilliant 

 light are seen to proc-eed from this luminous circumference, 

 which are distinct from the rest of the mass of light. When 

 the magnetization ceases, the lumiuous phenomena return to 



the condition familiar in the experiment, known under the name 

 of the Electric Er/g. 



There is some advantage in using for the experiment here 

 described Armstrong's hydro-eloctrio machine, in which the 

 boiler is made to communicate with the hook which is united 

 by a metallic connection to the ring of copper within the globe, 

 while the conductor which receives the vapor is put in connec- 

 tion with the bar ot soft iron. Thus we have in the globe an 

 electric current of great intensity which may be changed in 

 direction, by inverting the connections. 

 [To he continued.) 



The Mints of the United States. 



BY PROFESSOR WILSON.* 



The transmissions of gold from the new state of California 

 have caused a corresponding increase in the gold currency of 

 the States, and have invested the Mint operations with more 

 general interest than under the previous ordinary circum.stances 

 they possessed. The same condition of things exists in this 

 country; and as it is intended to establish a mint in the gold 

 producing colony of Australia, I thought it desirable to obtain 

 as much information as I could in reference to the organ- 

 isation and working details of those in the United States. 



The head e.stablishment is at Philadelphia, and is called 

 " The Mint ;" there are also three " Branch Mints ;" — at New 

 Orleans, in Louisiana ; at Charlotte, in North Carolina ; and 

 at Dahlonega, in Georgia, respectively. The Branch Mint in 

 California, and the Assay Office in New York, are not yet com- 

 pletely organised. 



At the Mint in Philadelphia, gold, silver, and copper, are 

 coined ; at New Orleans, gold and silver are coined ; while 

 the branches at Charlotte and Dahlonega coin gold only. At 

 " The Mint," the executive staff consists of a director, 

 treasurer, chief coiner, melter and refiner, engraver, assayer, 

 and assistant-assay er. At the New Orleans Branch Mint the 

 staff consists of a superintendent, treasurer, melter and refiner, 

 and coiner ; and at each of the other two branch mints there 

 are but three officers, — superintendent and treasurer (combined), 

 as.sayer, and coiner. The several duties of the.«e officers, the 

 remuneration they shall receive for their sen'ices, and the 

 amount of security they shall give for the due perforaiance of 

 them, are duly prescribed by an Act of Congress supplementary 

 to the Act entitled " An Act establishing a Mint and regula- 

 ting the Coins in the United States ;" this latter act giving 

 all the details referring directly to the coinage of the country. 



At the United States Mint at Philadelphia, the salaries are 

 fixed as follows : — Director, £3500 ; treasurer, §2000 ; chief 

 coiner, 82000 ; melter and refiner, $2000 , assayer, S2000. 

 At the New Orleans Branch Mint the salaries are, to the su- 

 perintendent, $2500, and $2000 each to the other officers ; and 

 at the other branch mints the superintendents receive $2000, 

 and the other officers $1500 respectively. In each of the es- 

 tablishments the appointment of as.sistants, subordinate officers 

 and servants, is left entirely in the hands of the chief of the 

 diflferent departments. 



In visiting the Mint at Philadelphia I had the advantage of 

 being taken through the several departments by the chief 

 coiner, Mr. Franklin Peale, and the melter and refiner, Professor 

 J. C. Booth, who kindly furaished me with the following dc- 



* From tho Special Report on the New York Indastrial Exhibition. 



