470 Miscellaneous Intelligence. 



powerful current of air will thus be established, which entering by 

 the vestibule, will pass into the theatre through the screen, carry the 

 flame and smoke towards the back of the theatre, and out at the 

 upper apertures on that side. That done, every means possible 

 must be taken to throw the inflamed wood-work towards the bottom 

 of the theatre, to prevent the calcination of the lar^e wall. The 

 firemen, in the pit, should water the wires of the metallic screen, 

 and extin<:^ish the flames near to it. Some of them, with lons^ 

 poles, should be ready to thnist any scenery or inflamed wood which 

 may fall a^*ainst the screen backwards, whilst others should watch 

 the body of the theatre to extinguish any small portions of fire that 

 misrht accidentally pass the screen. The fire thus confined to the 

 back of the theatre, would be more readily extinguished by the 

 ordinary means ; or if the fire happened On the other side of the 

 screen, then a similar system should be pursued, always considering 

 that part in which the fire is strongly established as a furnace, and 

 removing all burning portions as fast as possible from the part to 

 be preserved towards the place where combustion is allowed. — 

 Bui. Univ. E. vii. 15. 



5. Macadamised Roads. — The cost of converting Regent-street, 

 Whitehall, and Palace-yard, into broken-stone roads, has been 



£6055 8 3 

 Value of old pavement taken up and broken for 



that purpose 6787 7 



5^12,842 15 3 



Parliamentary papers. M. Post. May 19th. 



II. Chemical Science, 



1. Determination of the Electro-conducting Power of Metals. — 

 The following is a very simple and exact process by which M. 

 Arago ascertains the conducting power of different bodies for the 

 electric fluid, when the latter is accumulated upon large surfaces, 

 in a state of great tension. Suppose a conducting wire to be con- 

 tinued from the external coating of a battery, in a rectilineal direc- 

 tion, for a certain length, and then ramifying in a certain number 

 of branches of the same metal, all equal in diameter, form, and 

 length, and reuniting in one common point. Steel needles are to be 

 placed transversely across the straight part of each wire before and 

 after the ramification, and the electric discharge is to be passed 

 through the system. It will pass undivided through the first con- 

 ductor, but be separated in the different branches into equal pro- 

 portions. The magnetization of the needles placed on the first 

 wire will be the measure of the effect produced by the whole quan- 

 tity of electricity; the magnetization of those placed on the rami- 

 fied wires will measure the effect produced by a certain fraction of 

 that quantity ; as the third, if there be three branches ; or the tenth/ 



