THE BATTERING-RAM. 153 



and the contents of the box were little more than a congeries 

 of Wax-moth galleries. Even the Wasp and Hornet nests 

 which had been placed in the same box had been attacked, and, 

 although they had not been so utterly destroyed as the waxen 

 cells, they had been sufficiently injured to render them unfit 

 for exhibition. 



Many other insects work on the same principle. Certain 

 Termites, for example, construct tunnels of clay, in order to 

 conceal them on their travels, and have the art, even in the 

 hottest and driest weather, of mixing their clay with some 

 liquid which renders it, when dry, nearly as hard as stone. 

 Indeed, there have been instances where the Termites have 

 attacked the wooden beams of houses, and literally transformed 

 them into beams of stone. 



Then there are many Ants, notably several species of South 

 America, which cover their approach by tunnels, and never 

 venture into the open air. 



Gravity as a Propulsive Agent. 



The two figures on the accompanying illustration will almost 

 speak for themselves. 



We have already seen how the same force of gravitation 

 which causes the avalanche to thunder down the precipice may 

 be utilised as a means of projecting missiles in time of war. 

 When, however, the stones or beams were once sent on their 

 destructive mission, they were out of the control of those who 



RAM. HEAD OF BATTERING-RAM. 



launched them. We now come to a modification of the force 

 of Gravity, by which the missile, if we may so term it, is kept 

 undar control, its power increased or diminished at will, and its 

 point of attack shifted according to the requirements of the 

 moment. 



Before the invention of artillery, the Battering-ram was by 

 far the most formidable engine that could be brought against 

 a fortified place. The principle of the Battering-ram was 



