866 Transactions of the American Institute. 



by electricity when very finely powdered substances, such as lycopo- 

 diura, are applied to an insulator. The new figures are formed on 

 the conducting surface, and are less dependant than the Lichtenberg 

 upon the peculiar kind of electric developer em])loyed. 



Improvement in Rolling Ieon. 

 Mr, Robert Rohinson of England has invented an improved roller 

 for manufacturing iron plates, bars, rails, ttc, which has been suc- 

 cessfully used at the Coalbridge Iron Works. The new roller is 

 tubular instead of solid, with a stream of water inside for the pur- 

 pose of keeping it comparatively cool and preventing undue expan- 

 sion. It is from seven to eight cwts, per ton ligliter than the 

 common roll, and the brass bearings are proportionately lighter. 

 The saving in first cost is estimated at fifteen per cent, and the new 

 rolls will last much longer than solid rolls. Ko scales stick to the 

 hollow rolls; therefore, the finished bar or plate made by them -pre- 

 sents a finer surface. 



Leak^vge Al4km. 

 Mr, F. de Coninck, ship owner, of Havre, France, has been led, by 

 recent accidents which have occurred from the entrance of water 

 into ships' holds not being discovered until the pumps were of no 

 avail, to design an apparatus for the purpose of indicating, at all 

 times, by an alarm, the rise of water in the hold. The principle of 

 fhe apparatus is that of a fioat in communication with an alarm- 

 bell, provided witli a ratchet and detent arrangement and counter 

 weight, which in their normal condition, maintain the apparatus in 

 equilibrium, but, as soon as the float rises by the ascent of water in 

 the hold of the vessel, the equilibrium is destroyed, and the ratchet 

 which prevented the movement of the striking apparatus being with- 

 drawn, the alarm is set in motion. The only condition necessary 

 to the working of this indicator, is the winding up of the weight, 

 which gives motion to the striking machinery. 



The Ear. 

 Dr. A. Cousin's paper, in a recent |n umber of a French journal, 

 treats of injections and instillations into the ear. II« considers luke- 

 warm water the best and most innocent emollient that can be used 

 for that delicate part. Milk, various oils, mucilaginous and narcotic 

 decoctions, which the public believe so safe, leave organic substances 



