NOTES BY THE EDITOR. IX 



crease our knowledge of its illuminating power. Articles will 

 be found on page 90 bearing upon this subject. 



Prof. Tyndall says that the superiority of gas for light-houses 

 over oil is rendered very manifest by the experiments lately 

 instituted at Howth Baily and Wicklow Head. 



One cannot fail to notice the impulse which the completion 

 of the Pacific Railway, the Suez Canal, and the French Atlantic 

 Cable have given to the desire implanted in the human breast 

 to overcome natural obstacles. M. Lesseps advocates flooding 

 the desert of Sahara by means of a canal, and thus afford com- 

 munication with the interior.of Africa. 



Among the projects that have been re-agitated the past year, 

 are the project of a canal around the Falls of Niagara ; a re-en- 

 largement of the Erie for vessels of 1,000 tons; one across the 

 Alleghanies in Virginia; one through the Isthmus of Darien, 

 the expedition for surveying which has already started, and 

 one from Huron to Ontario. In tunnels we have that of Mt. 

 Cenis, 8 miles, and the Hoosac, 5 miles, in length, both in 

 rapid progress; one of wrought-iron tubes at London, and 

 another at Chicago ; tunnels proposed under the East and North 

 Elvers at New York ; under the Ganges at Calcutta, and under 

 the Straits of Dover. 



In view of past achievements, it is not safe to pronounce any 

 of these projects not feasible. 



In physical science, Tyndall commenced the year with a pic- 

 turesque account of a discovery of the peculiar action of light 

 upon vapors. 



In electricity we have no startling discoveries to chronicle. 

 M. Jamin, it is said, has ascertained that magnetism can be 

 condensed for a short period in the same way as electricity. 

 Prof. LeRoy Cooley, of Albany, has discovered a way of regis- 

 tering vibrations by means of electricity. His method will be 

 found on page 162. 



He dispenses with the sirene, and obtains a direct regis- 

 tration, the vibrating body itself opening\and closing a circuit. 



We have about the usual number of new batteries to chron- 

 icle. The combination of elements to produce currents seems 

 unlimited. 



The energies, however, of most of our physicists, both at 

 home and abroad, have been directed to the field of spectrum 

 analysis. 



