Proceedings of the Polytechnic Association. 893 



the top. This is the deepest subsoil plowing we have any account 

 of. 



CuKious Fact in Acoustics. 

 The firing of the guns at the late meeting of the Highland Eifle 

 Association at Inverness was heard distinctly, says a Scottish journal, 

 as far as Cairnorm hills and in the forest of Abernethey a distance 

 of fifty miles. The wind was favorable for carrying sound in that 

 direction, and there is a steady rise in the ground nearly all the way. 



Test for Albumen, 

 Dr. Mehu mixes in one part, by weight of crystallized carbolic 

 acid or phenol, one pait of commercial acetic acid and two parts of 

 ninety per cent alcohol. In a case of albumenaria, to detect albumen, 

 add to 100 grammes two centigrammes of commercial nitric acid, 

 and after thorough mixing add ten of the carbolic acid solution. 

 The reaction produced is said to be very superior to that in which 

 nitric acid alone is used. 



Plumbago as a Lubricant. 

 The Journal of the Franklin Institute says : " Every one knows 

 that for heavy machinery plumbago is a good lubricant, but every 

 one does not always think of applying it M'here it would serve best. 

 It may be of value to some of our i-eaders to know that a planer, 

 whose bed-plate required the force of eight men to slide it when 

 lubricated with the best ordinarj^ material, was easily shifted with 

 one hand when plumbago of good quality was applied. 



A New Russian Cannon. 

 A twenty-inch gun, cast at Perm, has i-ecently been tested under 

 the direction of Maj. Gen. Pestitch, conmiandant of tlie Cronstadt 

 artillery. The gun was fired 314 times ; each projectile weighed ten 

 hundred weight, and the charge of powder required was 130 pounds. 

 The weight of the gun is about fifty tons ; the recoil was seven 

 feet; the initial velocity, 1,120 feet per second, and the percussive 

 force at a distance of fifty feet about 10,000 tons. The official report 

 states that this is the most poweiful gun in Europe. 



Tanned Cotton Cloth. 

 The Paris Cosmos states that cotton fabrics have been treated 

 with a solution of tannin in the same iiianner as liides are in the 



