198 OBSEBVATIONS ON THE WINDS. 



which blow to the Eastward of those meridians originate only within this 

 band. On the contrary, it is evident from the Tables that even if that 

 band forms the region where the Polar Current flows most strongly South- 

 wards, yet a quantity of narrower air currents take the same course, and 

 their interstices are filled up by currents of equatorial air of different 

 breadths, which flow more or less quietly side by side in opposite direc- 

 tions until the increasing differences of tension create a necessity for re- 

 storing equilibrium. 



In those regions of atmosphere lying to the Eastward of an equatorial 

 wind (which comes up with a low barometer), anefilux of the air takes 

 place (therefore a rapid fall in the barometer) with winds backing to S.E.; 

 meanwhile the S.W. wind advances, the barometer falls to its lowest point, 

 and the thermometer rises to its highest ; but the heavy rain which now 

 falls so lessens the tension of the Southern air, and the difference of pressure 

 becomes so great, that the polar current lying to the Westward rushes in 

 furiously, the wind vane quickly veers to West and N. W., and with rapidly 

 rising barometer equilibrium is restored amid electrical discharges, sleet, 

 and hail squalls. 



In all these conditions, which find their outward expression in the change 

 of wind direction, pressure, and temperature, neither the cyclonic theory 

 of the Tropics nor the so-called laws of gyration are wanted, which, if we 

 consider them in the most favourable light, are neither more nor less than 

 expressions for long-established views. 



(128.) British Isles. — " W^eather Charts and Storm Warnings" is the 

 title of a small work written by Mr. Eobert H. Scott, M.A., F.R.S., 

 Director of the Meteorological Office in London, as a help and guide to 

 the sailor in using the cone signals, and also to those studying the Weather 

 Charts now so generally inserted in the daily newspapers. In this book, 

 of which a revised edition was published in 1887, will be found all the 

 latest knowledge which has been gained relating to the Winds of the 

 British Isles. Another useful little work, giving much information in a 

 condensed form, is " Weather Forecasting for the British Isles," 1890, by 

 Captain Henry Toynbee, F.R.A.S., &c., from which we have already made 

 several extracts. We give below a short summary of the most interest- 

 ing facts. 



It has been found that nearly all our Storms are of a rotatory nature, 

 and travel from S.W. to N.E., or from the Westward towards the Eastward, 

 as is evidenced by the fact that out of twenty-three Storms felt in Hamburg 

 in the year 1869, twenty-two had previously passed over some portion of 

 the British Isles. 



As before stated, when dealing with the Storms of the North Atlantic 

 Ocean (page 183), these Storms are divided into two classes — Cyclonic, 

 in which the wind revolves against watch-hands around a centre of low 

 barometric pressure, and Anti-Cyclonic, in which case the wind revolves 

 with watch-hands, or in the same direction as the hands of a watch, around 

 a central area of high barometric pressure. These terms are, however (as 

 before stated on page 185), only relative, having no reference to a high or 

 low level of the barometer, but to that level as compared with pressures in 



