L. MECHANICS AND ENGINEERING. 493 



to a brown black, becoming regularly darker with the increas- 

 ing heat, so that, besides learning the general effect of the 

 dangerous change, a little observation will serve to establish 

 the standards of correspondence of the temperature and the 

 color. lZ>, August, 1872, 88. 



FLORIDA SHIP-CANAL. 



A company has been organized, under the authority of the 

 State of Florida, for the purpose of digging a ship-canal 

 across the peninsula, to extend from St. John River, through 

 Lake Kerr and the Ocklawaha River, to Silver Spring, which 

 is the summit, and where there is an abundant supply of 

 water; thence westerly twenty-four miles to Blue Spring; 

 thence nine miles to Fort Clinch, on the Withlacoochee ; and 

 thence down this river nine miles to the Gulf a total dis- 

 tance of fifty-two miles. It is stated that any required depth 

 of water can be obtained, with a small lockage and moderate 

 expense of construction. If this idea be carried out, and also 

 that of constructing a canal across Delaware, New Jersey, 

 and Cape Cod, vessels will be able to pass readily during the 

 stormy season from one part of the Union to the other with 

 very slight exposure to the ordinary perils of navigation. 

 0Z>, October 6, 1872, 215. 



LIGHT-HOUSES IX THE UNITED STATES. 



The Light-house Board reports that there are now 573 

 light-houses along the coast and shores of the United States, 

 and 22 light-ships. Estimates have been made for new first- 

 order sea-coast lights at Cape Elizabeth, Maine, and Mono- 

 moy Point, Massachusetts ; for two steam fog-signals at Cape 

 Cod, one at the Highlands, and one at Race Point ; for light- 

 houses for signals at the mouth of Massachusetts Bay; for a 

 steam fog-signal at New London, Connecticut ; and for a 

 light-house foundation on Southwest Ledge, New Haven Har- 

 bor. Boston Transcript, Sejitember 0,1872. 



NEW LIGHT-HOUSES ON SABLE ISLAND. 



The department of Marine and Fisheries of the Canadian 

 government is now erecting two large light-houses, one on 

 either end of Sable Island. This, as is well known, is a large 

 island composed almost entirely of sand, situated about 150 



