AMERICAN INSTITUTE. 3Y3 



Aristarclius could be detected. The bright lines radiating from the moun- 

 tains were clear and distinct. One of Jupiter, showed his belts very well 

 marked, and his satellites visible. Now, assuming a high degree of per- 

 fection in astronomical photography, they may be illuminated to an indefi- 

 nite degree of brilliancy by adventitious, light to detect impressions invisi- 

 ble without it ? 



The distinguished astronomer, Le Verrier (glass-founder), has laid before 

 the Academy of Sciences, his great work La Reduction des Observations 

 faites aux Instruments Meridiens de TObservatoire de Paris, depuis 1800, 

 jusqu'a 1829. 



SPEED ON RAILWAYS. 



At a recent meeting at Birmingham, one of the most distinguished men 

 in the world (Lord Brougham,) suggested that " the speed of trains should 

 be limited to twenty-five or thirty miles an hour." Now, with proper care 

 and good management, a speed of seventy miles an hour can be made as 

 safe as one of seventeen. Accidents do not arise from the degree of speed, 

 but from bad construction or mismanagement. Good workmanship and 

 good management are required. To prevent a horse running away we 

 should not tie his legs, but put a good rider upon his hack ! 

 {From the American Mining Journal.] 



GRINDING QUARTZ FOR GOLD. 



In Piedmont, Italy, there are now gold quartz works which have been 

 in operation the last thousand years ! Not rich enough to pay by the 

 methods used elsewhere, here they roast the rock, then break it with a 

 hammer to lumps about 1| inches square ; these are fed to revolving mill- 

 stones, so set as to grind the quartz as small as Indian corn ! which is then 

 fed to other mill-stones so set as to grind these to the finest powder. 

 This they amalgamat-e in the usual manner. The stones are common burr, 

 and last several months, 



IGreological Institute of Vi«nna.] 



STRENGTHENING ELECTRO MAGNETS, 

 M. Schefeik, Engineer of the Austrian Imperial Telegraphs, has per- 

 fectly succeeded in this by using (instead of the copper wire of inconsider- 

 able diameter, in wrapping the iron cores,) ribbons of copper, presenting 

 the edges to the core. 



GRANTHAM ON IRON SHIP BUILDING 

 Speaks of Shortridge, Howell & Jessop's homogeneous metal, and its 

 advantages for plating iron ships. An inch bar of it has been tested at 

 the Liverpool Cable Testing Machine. It broke under a strain of fifty- 

 three tons ; rather more than double the best English bar iron. This 

 metal is ductile, malleable, and welds with facility. It resists oxidation 

 and fire far better than common iron. 



Mr. John Laird, the great pioneer of iron ship building, has taken the 

 initiative in the use of this homogeneous metal, for ship building purposes, 



