mi 



SCIENCE. 



[N. S. Vol. HI. No. 70. 



in the higher layers ; from 35° to 90° lati- 

 tude two easterly components, making a 

 maximum and I'apid eastward drift in the 

 neighborhood of 54°. In the vertical, from 

 0° to 20° and from 70° to 90° latitude, 

 there is an upward component ; from 20° to 

 70° latitude, a downward component. The 

 cyclonic and the anti-cyclonic motions to 

 some extent spring out of these, but the 

 really active part of them is confined to the 

 strata within two miles of the ground, and 

 yet the precise course of the stream lines is 

 not comprehended throughout their extent. 



Much light has been thrown upon the 

 obscure features of these problems by obser- 

 vation at high altitudes, and especially by 

 measurements of cloud heights and veloci- 

 ties, but still much remains to be done to 

 reach satisfactory conclusions. It is thought 

 that some account of these observations to be 

 undertaken shortly, and a reference to the 

 important literature regarding them, may be 

 of interest to those who have these subjects 

 at heart, especiallj^ those who are cooperat- 

 ing in the work of the U. S. Weather Bureau. 



The attention of meteorologists, in the 

 early developments of the subject were, 

 naturally almost exclusivelj^ confined to 

 studies on the data furnished by the lowest 

 stratum of the atmosphere. The circula- 

 tion and physical conditions of the air in 

 the higher strata were investigated to some 

 extent by means of the theoretical consid- 

 erations and the general movements of 

 clouds. It has, however, become apparent 

 that a scientific knowledge of the action of 

 the currents in cj'clones and anti-cyclones 

 can be obtained onlj^ by a determined at- 

 tack upon the physics of the upper levels 

 of the atmosphere. Progress in meteor- 

 ology, working along the original lines at 

 the surface of the ground, has for a number 

 of years been disappointing, and it is well 

 known that in the art of forecasting almost 

 exactly the same methods that were per- 

 fected twenty years ago are still employed. 



There seems to be little hope of improving 

 this state of afiairs, unless a radically new 

 way of dealing with the data can be de- 

 vised, which will efficiently supplement the 

 system now in use. 



The Chief of the Weather Bureau has 

 expressed the opinion that there are two or 

 three lines of investigation promising the 

 wished-for results. One is the practical 

 development of the knowledge already 

 gained regarding the polar magnetic radi- 

 ation from the sun. The serious difficulty 

 in the way of doing this has been the ex- 

 pensive and complicated nature of first- 

 class magnetic observatories, which must 

 necessarily limit the number in the United 

 States. What was wanted was a simple, in- 

 expensive and yet reliable instrument, that 

 could be utilized as readily as a barometer, 

 thermometer or a watch. It seems now, 

 after a couple years of trial, that such an 

 apparatus is in hand, and a record of its 

 performance will be published, with a de- 

 scription of it, beginning in the January 

 number of the Weather Revieio for 1896. 



Another process for getting at the action 

 of the upper air is the transportation of 

 barometers, thermometers and other appa- 

 ratus into the higher levels. This can evi- 

 dently be done by mountain stations, bal- 

 loons and kites, and experiments are being 

 conducted by the Weather Bureau to carry 

 out this purpose as far as practicable. 



A third line of investigation is the study 

 of the clouds in all their aspects ; the con- 

 ditions under which the several forms are 

 developed ; the heights of the several levels, 

 the variations of the same in the diurnal 

 and annual periods, and particularly in 

 connection with the cyclonic circulation of 

 the lower strata ; the direction and velocity 

 of movement in the general circulation of 

 the currents of the atmosphere as well as 

 around the barometric maxima and minima. 

 The fact that clouds are present almost 

 every day in a series of forms which pass 



