SCIENTIFIC FAITH AND WORKS 109 



seemed menaced, and other natural resources had to be developed, and 

 more efficient methods of application found. Thus in our day the de- 

 velopment of the internal combustion or gas engine, which threatens 

 to crowd the steam engine to the wall, has finally permitted the appli- 

 cation of petroleum, which by the aid of chemistry has furnished not 

 only great stores of energy, but numerous useful products. Not the 

 least important aspect of the power development is that part which is 

 applied to transportation. The covering of the whole known world 

 with lines of railway has made possible and easy movements from 

 place to place not only of peoples, but of products, so that while a few 

 centuries ago a large proportion of the population never moved more 

 than a few miles from their birthplaces, being as good as fettered to 

 the soil, now even the poorest may be easily displaced from country to 

 country, the seas being no more of a barrier than the land. The in- 

 crease of education by travel, and the tendency toward peace pro- 

 duced by the increased acquaintance of nations with each other, is not 

 to be overestimated. Perhaps no more impressive example of man's 

 power over nature is to be found than the sight of a great ocean 

 steamship, lying at her dock and towering over the surrounding build- 

 ings, or ploughing her way at express speed over the stormy waves, 

 whose power she hardly seems to feel. A notion of the huge demands 

 made by ocean transportation on our resources of energy is obtained 

 when we think that one of these marine monsters is using sixty or 

 eighty thousand horsepower, while an express train uses from a thou- 

 sand to fifteen hundred only. In view of this depletion of our coal 

 supplies the question of water power has become urgent, »and science 

 has succeeded in bridling our rivers and waterfalls for further supplies, 

 while the transmission of this power by electricity has made manufac- 

 turing possible where it was not before, and is now being applied to 

 transportation on a large scale. Not to be neglected in connection 

 with the application of power is the question of illumination. When 

 we think of the dark and dismal nights in the cities, not only of an- 

 tiquity, but even of two centuries ago, making it impossible to go out 

 in safety at night, and encouraging all sorts of crimes of violence, we 

 must consider the successive application of gas, oil and electricity to 

 have had no mean influence on the habits of mankind. The use of 

 modern illuminants, especially electrical, has made possible the per- 

 formance of more work, under more healthful conditions, and has 

 completely changed the habits of man as regards the hours of dark- 

 ness. Whether this has been entirely for his advantage we may leave 

 until later. 



Almost equally important with transportation is communication, 

 which has in like manner changed the possibilities and habits of man- 

 kind. At the time of our revolution it took weeks to get any news to 



