i88i.] Offensive Manufactures . 13 1 
neighbours in space. It really has a source of new energy 
in its motion through space which may, as we have seen, be 
made available through the attractive or repulsive aCtion of 
other systems, its process of evolution at one period of time 
being reversed at another period. 
Again, in the case of two repelling spheres bringing each 
other to rest, with the conversion of their mass motion into 
heat, a portion of this heat is radiated into space. There- 
fore on their subsequent separation by repulsion, a part of 
their former energy of mass motion has been lost, and must 
be replaced from their original store of heat. Here, then, 
seems a source of a gradual and irreversible loss of heat 
into space, which must, after some interminable period, 
exhaust the available energy of the spheres and limit their 
activity. 
But this loss may be met by a gain in an opposite direc- 
tion. Attractive spheres will be met as often as repulsive. 
These, by the excessive increase of speed, may become 
greatly refrigerated, and receive radiant heat from space 
instead of radiating into space. Thus the loss of energy in 
the one case may be balanced by a gain of energy in the 
other. And finally there may be regions of space of a 
temperature sufficient to prevent or to reverse the radiations 
of the spheres. 
It seems, then, as if the universe may be organised on a 
self-regulating principle, all its changes being paralleled by 
counter-changes, its losses replaced by gains, so that the 
condition it now displays is a counterpart of the condition 
it has maintained throughout the eternity of the past, and 
will maintain throughout the eternity of the future. 
II. OFFENSIVE MANUFACTURES : 
A SUGGESTION. 
By An Old Technologist. 
& UCH has been already done in the way of rendering 
certain manufacturing and mining operations less 
noisome to the general public than was formerly 
the case. The production of black smoke beyond certain 
limits is interdicted,— at least if the local authorities choose 
