SCIENCE LETTER FROM PARIS. ■ 417 



And it has been estimated by very high authority that if a column of solid ice 

 forty-five miles square and of indefinite length were shot toward the Sun with the 

 velocity of a ray of light, and could all the heat of the Sun be concentrated on 

 the end of that approaching column of ice it would not only melt it but boil it to 

 steam and dissipate it in invisible vapor as fast as it could approach even at the 

 enormous velocity supposed. The amount of heat at the surface of the Sun must 

 be equal to what would be produced by the consumption of not less than ii,6oo,- 

 000,000,000,000 tons of coal every second of time. This is about equal to the 

 consumption of six tons of coal for every square yard of surface per hour. All 

 the coal known to exist in the Earth would suffice to keep up this heat about one- 

 eighth of a second. Now what proportion of this vast energy yerves any useful 

 purpose ? We know not that any part of it does except that which falls on the 

 Earth. That a large part of this is practically useless is evident from the fact that 

 this is the power that is concerned in the elevation of the vast quantities of water 

 from the Earth's surface noticed above, while much of it falls on deserts and 

 mountains where it is inevitably lost. But suppose all that falls on the surface of 

 the Earth answers some useful purpose, a simple calculation shows that only one 

 part in 2,000,000,000 of the Sun's light and heat falls on this globe. And if we 

 assume that all that is intercepted by all the planets of the solar system is 

 usefully employed it amounts to only 1-227,000,000 part of the whole. All the 

 remainder is waste so far as we are able to see. And it be true that the stars are 

 all suns this waste is to be multiplied by their number and magnitude. From this 

 brief review it appears that in both her materials and forces nature is exceedingly 

 prodigal. True, I have looked at this subject only from a practical, utilitarian 

 standpoint. Had it been viewed from the position of a scientist, a philosopher 

 or a theologian, the conclusion might and probably would have been different. 

 Some of the forces named will doubtless be partially or wholly utilized in the 

 future, but some of them must always remain as apparent examples of dissipation 

 of energy without any compensation. 



Hutchison, Kansas. 



CORRESPONDENCE. 



SCIENCE LETTER FROM PARIS. 



Paris, September 23, 1882. 



Paris is a beautiful capital, but it is not at all salubrious; this drawback is 

 due, not to its site, but to its sewerage, though the latter is most remarkable and 

 iu many respects fairly provided for. The houses are very substantially built, of 

 excellent stone and iron — wood being expensive and not sufficiently durable— and 



