Polytechnic Association Proceedings. gH 



balls in less than seven minutes — more than fourteen per minute — 

 ;md penetrated the thirteenth board. The Millbank rim-fii-e gun 

 fired ninety-nine balls in six minutes and a half — over fifteen per 

 minute — and penetrated the eleventh board. The Lamson gun 

 fii'ed twelve balls per minute. Ball's carbine threw seventy-five 

 balls in nine minutes and a half. The Remington breech-loader 

 fired one hundred balls in six minutes and fifty-three seconds, and 

 penetrated the eleventh board. The Prussian needle-gun was 

 tested in the same way as the others, and threw an average of six 

 t<) seven balls a minute, penetrating the eleventh board. It will 

 be noted that the action of the latter, which has acquired great 

 notoriety since the late contest between Prussia and Austria, was 

 inferior to most of the guns at this ti'ial, and further, that a num- 

 ber of the best American breech-loaders were not included in 

 that test. 



Mr. S. H. Maynard remarked, in relation to this item, that 

 advantage in a gun is not in the number of shots that can be fired 

 in short time, but in the accuracy of the ball. He had fired his 

 Prussian needle-gun twenty-one times in a minute, but this rate 

 could not be kept up. He would prefer to have our soldiers 

 armed with this gun. 



. FEOZEN GLYCERINE. 



At a late meeting of the London Chemical Society, Dr. IV. S. 

 Squire exhibited a fine specimen of frozen glycerine, and stated 

 that it was a portion of five tons he had imported from Germany 

 during the severe weather of the past winter. It was packed in 

 eight-hundred weight casks, and the contents of all of them proved 

 to be quite solid, and of a light brown color on their arrival in 

 England. The sample exhibited was a portion which had not been 

 liquified; its snow-like aspect was due to the removal of the color- 

 ing matter in the process of draining off the liquid portion. No 

 sugar, or other known crj'stalizable substance, could be detected 

 in the glycerine; the only impurity being about five per cent of 

 water, and a trace of coloring matter. The solid was slightl}'' 

 heavier than the liquid portion, one being 1.268 and the other 

 1.26. Mr. Squire had been unable to procure again solid glyce- 

 rine hy exposing the liquid di'ainings to intense cold in the labora- 

 toiy. Ice and salt, beside other freezing mixtures, had been tried, 

 but with no other result than making it more viscid; and frag- 

 ments of the solid dropped into the liquid did not lead to 'anj 



