28 PHYSICAL FORCE 



handling the moment before. So the scientific man 

 looks into the processes of nature, sunshine and fire, 

 storm and lightning and tempest, the battling of 

 the elements, the rushing tumult of man and his 

 machinery, the majestic circling of the moon and 

 planets ; stranger still, the silent, sleeping powers of 

 coal, explosives, food and fertilisers. He is no more 

 lost among them than the bank-teller is among his 

 miscellaneous collection of monies. He totals them 

 all in terms of energy, the power of working. The 

 enormous variety of activities they display bother 

 him not at all. 



Now, just as strict watch as the bank-teller keeps 

 on the credit and debit sides of the accounts of all his 

 customers, nature keeps over the energy accounts of 

 all its manifold processes. There is no work done 

 for which the energy required does not have to be 

 supplied, just as no money can be withdrawn from a 

 bank into which none has been paid. Money cannot 

 be spent twice, more must be forthcoming, and so it 

 is with energy. It can only be spent once, and, 

 whether spent usefully or uselessly, whether doing 

 enduring work or dissipated doing nothing perma- 

 nent, once spent it cannot be recovered. Very easy 

 indeed it is to waste energy. The performance of 

 any work demands so much energy, but any amount 

 more may be demanded if the worker is inefficient. 

 Abstraction or not, energy is as real as wealth, I 

 am not sure that they are not two aspects of the same 

 thing. The one drives the commercial and industrial 

 activities of men, and the other the whole physical 

 activities of the entire universe. 



Human beings and beasts of burden were at first 

 almost the sole sources of useful energy, the only 

 available labourers to overtake the heavy work of 

 the world. For countless ages the inanimate energy 

 of nature, of wind, waterfall and fire, proved too 



