294 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1908. 



complete system of conducting network over and on the buildings, 

 seems to be efficacious. 



Despite all precautions disasters of great magnitude will occur in 

 modern explosives works. This is, no doubt, in the first place, due to 

 the fact that quantities are nowadays made in such works which were 

 not dreamed of thirty years ago. For instance, the works at Modder- 

 fontein and Somerset West produce annually over 10,000 tons of 

 dynamite, and several other works run them very close. Such an 

 enormous output requires a very considerable number of buildings, 

 and consequently the chance of damage to life and property is greatly 

 increased. The construction of factories has, on the other hand, pro- 

 ceeded on somewhat orthodox lines, and not always, perhaps, with 

 due regard to subdividing and minimizing risks. 



Another reason for such catastrophes is the want of appreciation of 

 certain inherent dangers. The author has always warned manufac- 

 turers and users alike that the function of an explosive is to explode, 

 and that although certain compositions are almost insensitive to ordi- 

 nary impulses, such as blows, friction, etc., yet he never believed that 

 any explosive existed which under favorable conditions and by proper 

 means could not be made to explode. It is true that continental rail- 

 ways carry certain explosives, like ammonium nitrate mixtures, by 

 ordinary goods train, and the author believes this to be an example 

 w^hich might be quite safely followed by British railway companies 

 in the best interests of the public. There is no danger attached to any 

 of these explosives when in the safe custody of a railway van, and 

 when they do not come into contact with dangerous goods. 



Yet another warning to manufacturers may not be out of place. 

 Special attention must be paid to prevent any accumulation of dirt in 

 places liable to exposure to heat. In the French powder factory at 

 Saint-Medard the explosion which occurred in 1891 could be clearly 

 traced to gun-cotton dust lodging in the joints and* cracks of a wooden 

 workshop.* Do factories even now take every precaution to prevent 

 the accumulation of dirt of this kind? The author has reason to 

 doubt it, and a clean-up at a factory which he witnessed a short time 

 ago was quite an eye-opener. He can only warn those concerned that 

 every building where explosive dust can be produced, and every ap- 

 pliance and utensil therein, should be periodically and thoroughly 

 cleansed and overhauled. Imagine a drying tray, covered underneath 

 with canvas, on which gun cotton or powder is dried all the year 

 round, and ask yourselves what the chemical stability of the dust may 

 be after a year's exposure to a temperature of 40° C. (some factories 

 dry at 50° C), and whether a material dried on such a tray is fairly 

 treated. 



« Memorial des Poudres et Salpetres, 1894, p. 7. 



