the canal-barge could do so much damage, what, it was asked, would be the effect of an explosion of the 2,000 tons at Purfleet? Attempts were made to calculate the radius of destruction by Mallet's formula for the effect of bursting shells—the fact being disregarded that the bursting of a shell and the blowing up of a magazine are essentially different affairs. We were told how all East London would suffer from the shock, how several villages in Kent and Essex would be destroyed, and how trains would be thrown off the railway-lines, gasometers wrecked, and a wide district plunged into darkness. We must not forget that an explosion in the open country would have relatively much less force than an explosion in the midst of closely-built streets like those about Regent's Park. An explosion at Purfleet would be very terrible, but probably not half so destructive as one might expect at first sight. Then the Government must keep this large store of powder somewhere; 50,000 barrels could not be manufactured on an emergency, and Purfleet offers advantages in the way of safe and easy transport from Waltham, and shipment to India and the colonies, which mark it as a good site for our chief magazines. The gunpowder might indeed be distributed in numerous magazines, at various points along the lower part of the Thames, but this would really be to increase the chances of an explosion; for, the more numerous is the staff of superintendents and store-keepers, the greater is the danger of carelessness on the part of some among them.
Many a one has said, with the foppish young lord, who so much excited the anger of Hotspur at Holmedon:
"... That it was great pity, so it was,
That villainous saltpetre should be digged
- The explosion of a large magazine is really the successive explosion of various portions of its contents, not the detonation of the whole mass. This is why it is fallacious to attempt to estimate the effect of the explosion of 2,000 tons by comparing it with the explosion of a large shell, or of a few barrels on board a barge.