Arizona republican., 1898-11-16
FINDING THE EARTH'S ACE
Interesting Temperature Experi-
 menfS at Harvard.

Tn the geological laboratory of liar yard university an interesting series of expetifnents is being carried on to de- termitfe the aga Of the earth. The question is an old one. and many guesses Of more or less scientific eX- actness have been made in the past en- deavors 10 solve it. These have been based for the most part on the situa- tfon and formation Of rock and earth deposits or the decay of vegetable mat tsr. Professor B. o. Pierce and R. w Wilson, who are carrying on the pres ont tests. are working by a new pro- cess, which involves the use of mechan- ism for testing the conductivity or diff ferent grades of rock taken from diff ferent places, including the deepest hole that has ever been sunk in the earth. Incidentally the process also in wolves interesting mining problems, namely, the getting of gold from Vsfy deep levels and other questions Of deep shafting. It will probably settle the uuestfon of why certain parts of the interior of the earth are hotter or cold CT than other parts, laying down rules of scientific accuracy.
 The investigations are being carried on under the auspices Of the RumfoFd fund, and the professors who are con- ducting them are being supplied with material for the research by Professor Alexander Agassiz. Professor AgassiZ is chief owner of the Calumet and Hecla mine, the deepest ill the world The upper levels of this mine have been worked out, but as the shafts have been driven deeper and deeper the ore continues as plentiful as ever. I'm mense fortunes have been taken out of this great hole, and It Is Of value to scientists because the shaft, being now nearly a mile deep, has permitted ex- amfna ton of the interior of the earth such as has not been had before. It has been agreed among scientists gen orally that raging fires no longer exist in the interior of the earth. They be- ieye that the center of the earth IS very hot, but that this latent heat is what remains of the cooling process which has been going on for millions of years Like a fallen cannon ball, the earth is cooling off from the surface toward the center, but the general pres sure on all sides prevents the conha- grafton from raging within. Accord ing to this hypothesis the temperature ought to increase gradually but surely as the earth is penetrated. This mas proved to be the case in every dee2 hole which has been dug in the earth
 
 In a well which is over five thousand fees deep near Pittsburg, Pa, Professor Hallock of Columbia college found that the temperature rose 1 degree for every fifty feet the thermometer was lowered At five thousand feet the temperature was found to be 1909 de- grees Fahrenheit. At 5,502 the tenn perature was 12S degrees. In another deep well near Wheeling, Pa., the tsmperature at 4,500 feet is no degrees. In the Sperenberg salt well near Der lin, Germany, the temperature at A. ITO feet is 110 degrees. The Schala- dabach salt well, near Leipsic, has temDerature of 1855 degrees at 5,14O feet. Yet these temperatures are sur passed as far us rapid rise is con- cerncd, in holes bored in geyset regions. In the Sutro tunnel which does not go far beneath r,he surface, the heat is so intense that the men employed there in are compelled to work in twenty minute shifts.
 Now, all this is directly in contra distinction 70 what has been found to exist in the Calumet and Hecla mine. At a depth of mile the laborers work all day in tempera ture of 70 degrees, which condition, it must be added, is not brought about by any elaborate sys- tenn of ventilation. Seventy degrees is the natural temperaturs at the bot tom Of the mine. Professor Agasslz has made some elaborate experiments in testing the general temperature of the mine. He caused to be placed at regular depths number Of thermom- eters. He had thsm walled up in inches ill the rock and left them there months at a time. These thermone- ters were self-regfstering. That is, the mercury would ascend to the pEint of the highest temperature a-which acted upon them during their stay in the rock, but a crook in the m5rcufy tube prevented the mercury from ever de scending It could always rise, but it could never run back. Sc it was com pelled to stay at the point of greatest temperature When Professor Agassiz unearthed his instruments, however, he found Q great uniformity ill the general temperature Of his mine. Evl- dently the gradual rise in temperature did not hold in the Lake Superior dis trict, in which :he mine is located, as i. did elsewhere.
 The question now arose, Why was this so?'' Did it not have a strong bearing on the manner in which the earth cooled during geological ages?" Could not the condition be experi- mented upon and the results be utiliz- ed in some economic manner?' Clearly the condition surrounding the copper mines in Michigan was the result or the very low conductivity Of the sur rounding rock. Evidently this rock had not the power of conducting heat and cold to the degree manifested by rock in other parts Of the earth. The internal heat of the earth does not rise up through it as easily, for instance, as it does in the rock surrounding the we'll upon which Professor Halloek eX- perimented near Pittsburg, Pa. Just what is the difference, however, is not so easy to determine, and this really is what Professors Pierce and Wilson Of Harvard are trying to find out When they have done so they will have established the basis Of calculation from which some new facts may be gleaned and upon which some startling