September 5, 1890.] 



SCIENCE. 



'35 



go from Central Utah, at an elevation of 4,500 feet, north and 

 eastward to the high mesas of the Yampa and White Rivers, at 

 an elevation of 8,000 to 10,000 feet, where several feet of snow 

 cover the ground for two or three months. In that region during 

 the great snow-storms the wind usually blows from the south or 

 south-west. Some precipitation occurs on a north wind, but it is 

 preceded by west or south-west winds. It thus becomes evident 

 that the precipitation on the western slope of the mountains is 

 chiefly derived from the Pacific. Where does the moisture come 

 from that falls on the eastern slope? 



The larger part of the precipitation on the eastern slope of the 

 mountains takes place while the surface wind is blowing from the 

 north or some quarter from the eastward: hence it has often been 

 stated that this is Atlantic moisture. Doubtless much of it comes 

 to us from the Gulf of Mexico by way of the Great Plains, yet in 

 most cases it is easy to prove there has been a large supply from 

 the Pacific. ' 



First as to the storms of the colder months from October to 

 May. These storms usually cover large areas. The precipitation 

 is from stratus or cumulo-stratus clouds moving over the moun- 

 tains. Several days of south-west wind in most cases precede the 

 shifting of the wind into the north or some eastward quarter, at 

 which time the precipitation takes place. During some of these 

 storms the wind blows from some westward quarter for several 

 days, so that it is often certain that sufiBcient viind has passed 

 eastward to permit air direct from the Pacific Ocean to reach 

 eastern Colorado and the Great Plains. As the storm centre ad- 

 vances, this same air must often be deflected backward toward 

 the mountains. It is obvious that in the case of cyclonic storms 

 there is an influx of air from the west (the '•Chinook"' winds) in 

 the region south of the storm-centre. In the larger storms the 

 distance travelled by the wind is so great as to permit air direct 

 from the ocean to cross tbe mountains. 



Occasionally storms break upon us without the premonitory 

 south-west winds. Thus a blizzard struck south-eastern Colorado 

 Oct. 30, 1889. The winds had been light and variable. Suddenly 

 the wind shifted into the north to north east, and for several days 

 raged at a high velocity. There was a heavy precipitation of 

 snow, and not even the rotary snow-ploughs could keep the rail- 

 roads open for travel. Several thousand miles of wind from the 

 direction of the plains and Missouri valley were driven obliquely 

 up the slopes of the mountains. The signal maps show that the 

 storm-centre passed north-eastward over northern Texas, and the 

 area of west winds was far south of here. Over Mexico and 

 Texas there must have been a large movement of Pacific air east- 

 ward. 



Second, the summer thunder-storms. These also are preceded 

 by west to south-west winds. In general, the longer the west 

 winds continue, the more violent will be the storms when the 

 final break-up comes. A common type of development of the 

 July storms is tbe following. Warm winds begin to blow from 

 tbe south-west, and continue four or five da} s. The temperature 

 becomes progressively hotter. ."Some day we see a cumulus-cloud 

 over the mountains begin to throw out filmy streamers above and 

 a fringe beneath. It rains a little above timber-line, and there 

 may be a discharge of cloud-lightning. Then, as the cloud passes 

 eastward-over the plains, it loses its ominous fringe, and becomes 

 an ordinary sleepy cumulus with a sbaiT)ly defined edge. Next 

 day the attempt at a storm is repeated, the fringe is longer and 

 the cloud is larger, but the ranchman who is wishing for rain 

 looks on in disgust at the abortive effort, and remarks that there 

 is a lack of ginger in the upper air. Meantime the general move- 

 ment of the lower mile or two of the air continues from the 

 south-west. After a few more days of failure, we some day see 

 high cirrus streamers and films begin to form before noon. Soon 

 after, there are big cigar-shaped masses of cirro-stratus far below 

 the cirrus. Still farther below are innocent-looking cumulus- 

 clouds with rather definite margins. As the afternoon advances, 

 one of these begins to bristle with an indefinite fringe above and 

 below. The fringes grow longer. Presently a marginal belt of 

 rounded festoons appears outside the central fringes and beneath 

 the storm-cloud, while above it the high streamers radiate out- 

 ward in the sheafof-wheat pattern. In the mean time a halo, or 



part of one, has appeared around the sun in the higher filmy 

 clouds. Before midnight there will be hail .and cloud-bursts on 

 the mountains, and these storms wdl go hundreds of miles east- 

 ward onto the plains. It often happens that the first storms go 

 northward or north-eastward. The next day they shift toward 

 the west. In a few da3's they will come from the north-west or 

 north. Then the air will be cool, the general movement of the 

 air is from the north, and there will be no more storms until after 

 another season of south-west winds. 



Thus the summer showers, as well as the winter storms, derive 

 most of their moisture from the Pacific. There are different types 

 of these local electrical storms, but they all are alike in one re- 

 spect: they appear as local disturbances in the midst of an area 

 of relatively heated south-west or west winds. 



The present summer has been remarkable for the amount of 

 Pacific air. Heretofore, during several years of observation, the 

 wind has never been known to blow briskly from the south-west 

 for more than one to three weeks without the formation of some 

 kind of storm, or at least attempted precipitation, which inter- 

 rupted the west wind. 



This year, during late May, June, and July, there were more 

 than two months of almost constant wind from the south-west 

 over the mountains. It should be noted that the wind in the val- 

 leys, near the base of the mountains, is often variable, and there 

 are local movements this way and that, while all the time the clouds 

 on the mountains show that the wind is there from the south- 

 west. Several thousand miles of air fresh from the heated regions 

 of Southern California, Utah and Arizona, have passed eastward 

 over tbe mountains. Hot weather prevailed simultaneously over 

 eastern Colorado, Kansas, Missouri, and eastward. Such a move- 

 ment I have not noticed before in eight years of observation. The 

 thunder-storms have this year been late in forming in Colorado, 

 notwithstanding the great supply of Pacific air. For nearly two 

 months the clouds seemed to be at a rather low level in the air, 

 and there was much less of the high cirrus than usual. No solar 

 halos appeared till about the middle of August. Their appear- 

 ance was followed by very violent hail- storms and wash-outs. In 

 short, we appear for once to have had for most of the summer too 

 much Pacific below, and too little Arctic up above. 



It is noticeable that the tornado belt this summer lies far to the 

 north and east. Is not this the result of the vast body of Pacific 

 air which has invaded the Mississippi valley? It appears as if for 

 some cause the meeting-ground of the warm and cold currents 

 had, during the early summer, been pushed north-eastward to the 

 line from Minnesota to New England, instead of the ordinary 

 Missouri-Ohio line. G. H. Stone, 



Colorado Springs, Aug. 23. 



Professor A. Graham Bell's Studies of the Deaf. 



I AM always ready to welcome intelligent criticism of my labors 

 on behalf of the deaf; but the articles published in Science (Aug. 

 15, pp. 85-88; Aug. 39, pp. 117-1.9) from the pen of Mr. W. J. 

 Jenkins unfortunately contain so many misstatements of fact as 

 to render reply distasteful. 



Mr. Jenkins commences his criticism (p. 85) by " entering a 

 gentle protest " against the truth of a statement T never maie; and 

 he ends it (p. 119) with a long paragraph containing a series of 

 statements relating to the census of 1880, no one of which is cor- 

 rect. The intervening matter is so full of inaccuracies, that I 

 should take up a great deal of your valuable space were I to at- 

 tempt to point them all out. 



His chief objective is an attack upon what he calls my " theory 

 of a deaf-mute variety" (p. 85); but he nowhere states exactly 

 what this theory is, so as to enable your readers to judge for them- 

 selves whether or not his attack is well founded. Let me there- 

 fore supply this deficiency. 



The theory referred to is contained in a paper, •' Upon the For- 

 mation of a Deaf Variety of the Human Race," which I bad the 

 honor of reading before the National Academy of Sciences, Nov. 

 13, 1883 (see Memoirs of tlie National Academy of Sciences, vol. 

 ii. pp. 177-263). 



In the preface (p. 130) the theory is formulated as follows: "If 

 the laws of heredity that are known to hold in the case of animals 



