90 ANNUAL OF SCIENTIFIC DISCOVERY. 



PORTADLE ILLUMINATIONS. 



Mr. Alvergnint, a French electrician, has made an improve- 

 ment first suggested to him when using the tubes invented by 

 Giessler, which are cyHnders or bulbs of ghiss tilled with rarefied 

 gas that becomes luminous in the dark whim a current of electric- 

 ity is passed through it. The improvement consists in filling a 

 glass cylinder or phial, hermetically sealed, with a substance 

 which l)ecomes phosphorescent by the action of the frictional or 

 st;itic electricity. A tube of this kind may be of some service to 

 those on night duty; for all that is requisite to produce a feeble 

 and ephemeral light is to rub the tube briskly with a silk hand- 

 kerchief. 



WARMING CHURCHES BY GAS. 



The following method has been patented in England : A brick 

 chamber is made beneath the floor of the building, and a grating 

 is placed over it to allow of the passage of hot air. Beneath this 

 chamber an air-flue in connection with the flooring, and covered 

 with an iron grating, is introduced. By these means a current 

 of air is made to pass into the building, and this air i> brought 

 into contact with a ring gas-l)urner, which is supi)lied by an 

 ordinary main by means of a spanner, by which the amount of 

 heat can be regulated. Underneath this ring-l)urner is ])laced a 

 small cistern made of fire-clay, filled with water; the heat from 

 the gas-burner acts upon the water, steam arises, and this is 

 passed through pumice stone contained in a cylinder above the cis- 

 tern ; the use of this vapor is to moisten the atmosphere contained 

 in the reservoir. Around this is a circular cylinder made of fire- 

 clay, to contain heat. The whole is covered with a dome of fire- 

 clay. This dome is worked by a lever for the purpose of lighting 

 the ring-burner. By these arrangements, it is said that a pure 

 heat, free from smell or smoke, is obtained, and that with a very 

 small consumption of gas. 



GAS FOR LIGHT-HOUSES. 



A series of letters and reports sent to the Commissioners of 

 Light-houses and the Board of Trade has resulted in a request be- 

 ing made to Professor Tyndall, by the latter body, that he would 

 report u])on the proposal to substitute; gas for oil as an illuminat- 

 ing power for light-houses, as illustrated in the light-houses of 

 Ilowth liaily and Wicklow Head. Various experiments were 

 made at Ilowth Baily, and Professor Tyndall says that the supe- 

 riority of the gas over the oil flame is rendered very conspicuous 

 l)y these ex})eriments. The 28-jet-burner possesses two and one 

 half times, the 48-ict-burner 4i times, the 68-jet-l)urner 7i times, 

 the 88-jet-burner y| times, and the 108-jet-burner 13 times the 

 illuminating power of the 4:-wick flame. The oil lamp with 

 which the gas flame was comi)ared was the most perfect one em- 



