November 15, 1901.] 



SCIENCE. 



779 



due to some action of underground water. Be- 

 ing out of the reach of irrigation from the rivers, 

 and not having enough rainfall for agriculture, 

 the utilization of the High plains must be 

 chiefly as cattle ranges for which water may be 

 gained by wells and windmills. 



SOUTH SHORE OF HUDSON STRAIT. 



The forbidding character of a rocky upland 

 that has been recently and severely glaciated 

 and that still possesses a severe climate is well 

 portrayed in Low's ' Report on anExploration of 

 Part of the South Shore of Hudson Strait * * * ' 

 (Geol. Surv. Canada, Ann. Rep., XI., 1901, L.): 

 " The rocks met with are all of great antiquity, 

 and all are more or less altered by pressure, 

 induced by intrusions of igneous masses which 

 have folded the bedded series and have pro- 

 duced foliation in much of the otherwise mas- 

 sive granites, gabbros," etc. (p. 31 L.). The 

 crystalline rocks usually form a highland which 

 reaches altitudes between 1,000 and 2,000 feet 

 near the sea, and is often plateau-like in the 

 extent of its rolling uplands between deep and 

 sharp-cut valleys or canyons. Here rock and 

 boulders are abundant and soil is very scanty ; 

 here are abundant lichens and some flowering 

 plants, but no trees. Elsewhere the rocks are 

 stratified and gently inclined, forming low 

 ridges with steep outcrop faces and gentle back 

 slopes. Below 300 feet the surface is generally 

 mantled with marine clays, marked with ter- 

 races. But as the land rose from its postgla- 

 cial submergence, the headlands "have been 

 smoothed and polished by the pounding of float- 

 ing ice, which has removed nearly all the drift 

 from the points, leaving the solid fresh rock al- 

 ways exposed." 



the ORIGIN OF WATERFALLS. 



The 'Festschrift des Geographischen Semi- 

 nars der TJniversitat Breslau zur Begriissung 

 des XIII. Deutschen Geographentages ' con- 

 tains, among various essays, most of which turn 

 toward historical geography, an article on the 

 Origin of Waterfalls, by F. Sturm (pp. 122-132, 

 Breslau, 1901). Besides the numerous rapids 

 and falls which originate at points where a 

 young stream passes from a more to a less re- 

 sistant rock, or where a new course has been 

 taken in consequence of drift barriers, a num- 



ber of special cases are instanced, such as rapids 

 in a main stream where side streams form 

 boulder dams, illustrated by the Colorado in its 

 canyon ; rapids occurring where travertine is 

 deposited in a stream channel, as illustrated at 

 several points in Bosnia, and falls over fault 

 escarpments, such as those of the Oxara in Ice- 

 land. The order in which different kinds of 

 falls are presented is empirical rather than 

 genetic. 



Falls at the mouths of hanging valleys are 

 explained as resulting from the faster erosion of 

 the main than of the side stream ; strong glacial 

 erosion of the main valleys in excess of that 

 in the side valley is discredited. It is not 

 noted in this connection that hanging side 

 valleys with falls leaping from their mouths 

 into broad-floored main valleys are known only 

 in glaciated districts ; and that in non-glaciated 

 areas, side streams ' hang ' above their masters 

 only in the earliest stage of a new cycle ; ac- 

 cordant junction of side and main stream being 

 developed about as soon as the main stream 

 has graded its channel, and long before it has 

 broadly opened its valley floor. 



W. M. Davis. 



CURRENT NOTES ON METEOROLOGY. 



METEOROLOGICAL EQUIPMENT OF THE ' DIS 



COVERY.' 



The meteorological equipment of the British 

 Antarctic exploring vessel Discovery is de- 

 scribed by Dr. H. R. Mill in Symons^s Meteorolog- 

 ical Magazine for September. The Stevenson 

 screen contains a wet and dry bulb thermom- 

 eter, a mercurial maximum, and a Six's maxi- 

 mum and minimum thermometer. A barometer, 

 on the Kew pattern, is in the magnetic house, 

 and a barograph is kept in one of the compan- 

 ions. A thermograph and a hair hygrograph 

 are placed on the outer wall of the magnetic 

 house. The three recording instruments are 

 kept running to Greenwich time. The tem- 

 perature readings are checked by means of an 

 Assmann Aspiration Psychrometer, and sling 

 thermometers are also provided for comparison. 

 Rainfall observations are to be made with a 

 marine rain-gauge and evaporator of Dr. Black's 

 pattern. For carrying out observations in the 

 free air, a captive balloon is carried, and kites 



