43S GoIohpI Sir Frederic L. Nathan [Jan. 29, 



eutireij preve*its tlie further formation and separation of the small 

 traces of the nitroglycerine, which the after-separating bottles were 

 required to deal with. 



The advantages of the Waltham Abljey plant and system of 

 manufacture over others are briefly as follows :— 



1. Increased Safety. — By the abolition of all cocks through which 

 nitroglycerine had to pass, the risks attendant on their use have dis- 

 appeared. By the presence of cooling coils in the one and only 

 vessel in which nitroglycerine and acids are in contact, any undue rise 

 in temperature, always a possibility in the circumstances, can be at 

 once checked. It was not usual to have cooling coils in the separator 

 and after-separating bottles. 



'1. Rechiction in Total Elevcttion for, and Area of a Factory. — The 

 abolition of the separator, and the running off of the nitroglycerine 

 from the top of nitrator effect a very material saving in the height 

 required. 



The after-separating house being no longer necessary, nor the 

 separator house when one existed as distinct from the nitrating house, 

 the number of buildings, and therefore the ground area, is substanti- 

 ally reduced. 



;}. Reduced Cost of Production. — This results from the fact that 

 the capital outlay for a factory is much less, that fewer men are 

 required for a given output, that there is less plant and fewer build- 

 ings to maintain, and that the plant itself suffers slower deterioration. 

 Finally, the yield of nitroglycerine is increased by at least 5 parts for 

 every 100 parts of glycerine nitrated. 



the substitution, recently, of Nordhausen for ordinary sulphuric 

 acid, has further improved the yield of nitroglycerine, and whereas 

 a few years ago a yield of 210 parts of nitroglycerine for every 100 

 parts of glycerine nitrated was considered excellent, tlie average yield 

 at Waltham Abbey is now 280 per cent., a very high figure in view 

 of the fact that the theoretical yield is 246 • 74 per cent. The use of 

 Nordhausen sulphuric acid also permits of a considerable reduction 

 in the proportion of nitrating acid to glycerine, so that a larger 

 output is obtainable for any given sized plant. 



In the year 1846, Schonbein discovered guncotton. In the year 

 1886, that is, 40 years later, the French chemist Vieille invented his 

 smokeless powder for military purposes. This explosive, which was 

 primarily designed for use in the small calibre Lebel rifle, consisted 

 essentially of guncotton, and the secret of its success lay in the fact 

 that Yieille so altered its physical state that its rate of combus- 

 tion, when confined, was under complete control. This condition 

 was arrived at by treating the fibrous guncotton with suitable 

 solvents which entirely destroyed the fibre and converted it into a 

 colloidal horny substance quite devoid of all porosity. The gela- 

 tinised guncotton resulting from this treatment burnt, when ignited, 

 from the surface inwards, and by varying the surface area, any 



