g6 LIGHT SCIENCE FOR LEISURE HOURS. 



ticipating the requirements of those remote descendants 

 of ours. We should regard the consciousness of this 

 duty and its performance as signs by which the supe- 

 riority of our own over less civilised times is partly 

 manifested. As man is in dignity higher than non- 

 intelligent animals, in that he alone provides of his own 

 forethought for the wants of his children, so our gene- 

 ration would be raised in dignity above preceding gene- 

 rations if it took intelligent charge of the wants of its 

 remote descendants. We ourselves are now employing 

 stores of force laid up for us by the unconscious pro- 

 cesses of Nature in long past ages. As Professor 

 Tyndall has finely said, we are utilising the Sun of 

 the Carboniferous Epoch. The light ' which streamed 

 earthwards from the sun ' was stored up for us by the 

 unconscious activity of 'organisms which living took 

 into them the solar light, and by the consumption of 

 its energy incessantly generated chemical forces.' The 

 vegetable world of that old epoch 'constituted the 

 reservoir in which the fugitive solar rays were fixed, 

 suitably deposited, and rendered ready for useful appli- 

 cation.' What the vegetable world did for us uncon- 

 sciously during the Carboniferous Epoch, the scientific 

 world of our epoch must do for our remote descendants. 

 While we are consuming the stores of force laid up in 

 past ages for our benefit, we must invent the means for 

 obtaining directly from the solar rays fresh and inex- 

 haustible supplies of motive energy. 



(From the St. PauVs Magazine, November 1871.) 



