Page:Popular Science Monthly Volume 89.djvu/880

 Taking the Temperature of a Dam

Forty-seven thermometers are buried in the concrete of the Kensico dam

Bv Herbert Francis Sherwood

���The thermometers arc buried at predetermined levels and points in the dam and are connected by buried cables with switchboards at central points

��OSE fliiy, a year a^o, I paid my first visit to the ^ri-at Kensico dam, tliree miles north of White Plains, X. V.. <untcd atnoiiK the notable dams of the world. It is intended to form a storage reser\oir in the C'.itskill system of water supply which New ^'ork city is constructing at .111 expenditure of Si 77.ikh),(x#o. The i.ike of Citskill w.iter behind it will he .ipprnxim.iieK' four and .i h.ilf miles in lfn^;lh. 1 1 will ha\'e .» m.iximum de|)th of one hnndred and liflylue feet, and contain upw.niU (if lliirt\ liillion e.dlotis of w.ilcr.

��It was a hliak da\. The thermometer early in the mornini; hail registered zero. .•\ searchini; northwest wind swept down throngh the whole length of the gre.it l)asin in the Bronx valley and chilled to the ni.irrow those who went out upon the crest of the dam. .^ccompanie(l!)>• the division engineer, I descended from this exjiosed pi. ice to the long corridor extending for more than a third of a mile through the d.im. This corridor w.is opi'ii to the sk\- at iiitcr\.ils .111(1 I w.is astonislu'd at the w.irmth of the air encountered there.

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