180 



SCIENCE 



[Vol. LVI, No. 1442 



earth, though solid, is very hot. We know 

 that very great and unequal pressures exist at 

 depths of a few miles beneath the surface. 

 These are the conditions under which the 

 Archean rocks formed and no doubt are 

 forming. 



In the laboratory of the Master no reaction 

 occurs except according to law, and law is 

 eternal, unchanging. There is, perhaps, no 

 thought with which we may more appropriately 

 approach the engineering problems of the 

 Colorado Eiver. 



The engineers who will speak here of the 

 utilization of the Colorado will describe works 

 of great magnitude : dams surpassing any yet 

 built; reservoirs impounding millions of acre 

 feet of water; values of irrigated lands rising 

 to hundreds of millions of dollars; powers 

 which are to turn the wheels of industry from 

 San Francisco and Los Angeles to Denver. 

 But even so, they speak only as men, of the 

 little works of men. In the laboratory of the 

 Master their greatest accomplishment is infi- 

 nitely small and transient. 



A laboratory is a place where the forces of 

 nature work changes in material compounds 

 or crystal forms according to law. The me- 

 chanic, the physicist, the chemist arranges the 

 conditions of some desired reaction and under 

 the same conditions observes the identical 

 effects recurring endlessly, unfailingly. If he 

 makes an experiment the personality of the ex- 

 perimenter makes no difference. Even the 

 Master works by law and can not work other- 

 wise. Nor does time make any difference. A 

 billion years ago the law of gravitation held 

 the stars to their courses as it does to-day. In 

 the earliest conceivable eon of the existence of 

 matter the atoms moved to their places in 

 molecules in the same order as now. 



Yet there is a new development, no doubt 

 also in obedience to law, but so subtle that we 

 can not establish the relation. I mean the evo- 

 lution of mind, which can investigate law, 

 which can conceive and execute great works 

 that rightly constructed will stand for ages. 

 The mind can even trace its own evolution. 

 Backward from human thought to animal 

 instinct, from instinct to mere conscious ex- 

 istence, from consciousness to unconscious 

 molecular reaction runs the chain. It runs un- 



broken. Life is its characteristic. But if 

 thought is life, then is consciousness also ; if 

 consciousness is life, then is molecular reaction 

 also life. In this sense minerals are alive, for 

 they are chemical compounds which react to 

 their environment. The earth is alive, for the 

 reactions of its masses are evidenced in un- 

 ending change. 



The development of thought from uncon- 

 scious reaction has recently evolved reason. 

 Reason is so young, however, that it is still 

 embryonic and in many humans is in a larval 

 state. Nevertheless, no man becomes a scien- 

 tist or engineer without having to some degree 

 developed it and therein lies the hope of a 

 successful solution of the extraordinary prob- 

 lems of the utilization of the Colorado. 



The major difficulty in damming the Col- 

 orado is to establish the dam on a firm founda- 

 tion. Investigations of the river's bed show 

 that it is tilled to depths exceeding a hundred 

 feet with large boulders. The dam, if it be a 

 masonry or concrete structure, must be welded 

 to the solid rock in place. It will tax the re- 

 sources of the engineer to the utmost to dig so 

 deep through boulders and to place his foun- 

 dation structure during the few months be- 

 tween floods, which, if unrestrained, will 

 destroy it. 



. The presence of a boulder bed, of such depth 

 and composed of rocks of such size, was not 

 foreseen. It is due to the power of the floods. 

 At low water the river ripples impotently 

 around the stones. One can hardly conceive 

 that in flood it moves rocks as large as cabins 

 and buoys up a mass of them, rolling them 

 over one another with irresistible force. But 

 the evidence is there. It does. The bottom of 

 the river in flood is a torrent of rolling rocks, 

 of huge size. They roll, they jam, they tem- 

 porarily resist. The river piles up its waters 

 behind them. The rocks yield and are carried 

 crashing down the channel to come to rest as 

 the victorious waters roll on. 



It is one of the most daring conceptions of 

 modern engineering that this awful power 

 may be used to build the dam that shall chain 

 it. How, maj' best be stated in speaking of 

 the types of dams that are under consideration. 



The engineer and geologist are both cog- 

 nizant of the power of floods. But there are 



