208 



SCIENCE 



[Vol. LV, No. 1417 



decimalized; and equations in thermodynamies 

 require about half the old style multiplication 

 and division. 



It may be noted that, unlike the Fahrenheit 

 and Centigrade which depend upon the boil- 

 ing point of water, a variable quantity, depend- 

 ing upon pressui'e, and hence not the same 

 from one day to another, or even from one 

 place to another, the Kelvin-kilograd uses only 

 the freezing point. The effect of change of 

 pressure on the freezing point is so small com- 

 pared with the boUing point that the correc- 

 tion is practically negligible. 



Albxandee McAdie 

 Blue Hill Observatory, 

 January 30, 1922 



THE GEOLOGY OF WESTERN VERMONT 

 In a paper entitled "Studies in the Geology 

 of Western Vermont," published in the Twelfth 

 Biennial Report of the Vermont State Geolo- 

 gist, pp. 114 to 279, the writer has described 

 field relations among the lower and middle 

 Ordovician strata along the eastern shore of 

 Lake Champlaiu in the townships of Benson, 

 Orwell and Shoreham which seem best ex- 

 plained as gi'eat dislocations in the forms of 

 reverse faults and one or more low-angle thrusts 

 by which certain massive dolomite and lime- 

 stone strata of lower Ordovician age have been 

 broken and moved westward for indeterminate 

 distances over shales and interbedded black 

 slates and limestones belonging to the same 

 geological system, but undoubtedly younger in 

 age. 



Similar phenomena were described also for 

 the lake region near Burlington, where, how- 

 ever, thrust phenomena had long been better 

 known. In the northern areas, so far as 

 studies had then been carried by the writer, the 

 presence of lower Ordovician limestones on 

 middle Ordovician slates seemed largely eon- 

 fined to the islands of the lake, while on the 

 mainland of Vermont certain siliceous dolo- 

 mites and quartzites belonging to the Cambrian 

 system and to the lower Cambrian terrane were 

 found reposing on black slates with interbedded 

 limestone bands not very different from those 

 found beneath the lower Ordovician limestones 



on the islands and on the mainland farther 

 south in Orwell and Benson. 



In addition to the description of the more or 

 less clearly defined deformations just referred 

 to the writer offered field evidence in support 

 of the view that similar dislocations may prob- 

 ably define the fundamental deformational feat- 

 ui'es of the rocks within parts of the Taconic 

 Range, and along the "Vermont Valley" and 

 the western margin of the Green Mountain 

 plateau contiguous thereto, although within the 

 latter-mentioned areas the thrust relations have 

 been much disguised by normal faulting. 



In the summer of 1921 the writer continued 

 his studies in western Vermont among the 

 islands of Lake Champlain and along the main- 

 land in Phillipsburg, Quebec, and in the Ver- 

 mont towns of Highgate, Swanton, Sheldon, 

 St. Albans, Georgia, Fau'field, Fairfax, Milton 

 and Colchester. Although there are present in 

 these areas certain differences in respect to de- 

 formation and erosion, with which in some 

 degree apparently are to be correlated the 

 former extent and present boundaries of the 

 lake in its northern portions, and also certain 

 geogi'aphical variations, chiefly in the rocks 

 composing the lower Cambrian beds in north- 

 ern Vermont, the major thrust relations are 

 clearly defined. Many interesting structural 

 details were noted. 



It is purposed, at the first opportunity, to 

 continue these later studies thus begun and to 

 publish a second paper on the geology of west- 

 ern Vermont, dealing chiefly with deforma- 

 tional features among the islands of Lake 

 Champlain and along the Vermont shore region 

 of the lake as far south as Shoreham.^ 



C. E. Gordon 



Amherst, Mass., 

 November 1, 1921. 



ACUTE SENSE OF SOUND LOCATION 

 IN BIRDS 



In a recent issue of Science,^ Dr. A. G. 

 Pohlman, of the St. Louis University School of 

 Medicine, briefly discusses some matters per- 

 taining to the ability of birds to locate the 



1 Published with the consent of the Vermont 

 State Geologist. 



