190 OBSEEVATIONS ON THE WINDS. 



experience since that date has not been so satisfactory, and our own 

 Meteorological Office has given up for the present any attempt at predict- 

 ing Storms crossing the Atlantic. It is impossible to say that any Storn? 

 leaving the American shore will reach us, and, if it does, vyhat part of the 

 European coast it will first strike. 



Captain Hoffmeyer, of the Danish Meteorological Office, in a pamphlet 

 published in 1880, discussed 285 Storms, which occurred during a period 

 of 21 months. The results seem to show that only about 25 per cent, of 

 our Storms could possibly have been telegraphed from the United States. 

 Of 59 Storms which left the American coast in 1879, 37 (63 per cent.) 

 crossed to Europe, the time across averaging five days, or about 18 miles 

 an hour. The late Professor Loomis, the celebrated American meteorologist, 

 from his observations, considered that 47 per cent, of the Storms which 

 left the American coast arrived on the European coast, and he states, in 

 one of his Contributions to Meteorology, that "when Storms from the 

 American continent enter upon the Atlantic Ocean, they generally undergo 

 important changes in a few days, and are frequently merged in other 

 Storms which appear to originate over the ocean, so that we can seldom 

 identify a Storm in its course entirely across the Atlantic."* 



(126.) In the publication of the Meteorological Office mentioned below,f 

 and in any series of Weather Charts published, the fact of Storms travel- 

 ling Eastwards is very lucidly shown in the diagrams by the daily positions 

 of the isobars ; and in the remarks given hereafter on the Winds of the 

 British Isles, some further remarks will be found, showing that the pro- 

 gress of the main body of the air is to the North-Eastward across the 

 British Isles. That it occasionally travels to the South- West ward is also 

 mentioned. 



The chart for each one of the 11 days embraces the observations of about 

 30 ships, together with those of many land stations. Captain Toynbee 

 draws the following conclusions from the study of these charts. 



1. As to the origin of the numerous gales experienced during the 11 days 

 with which we have been dealing. 



By referring to the charts it will be seen that almost invariably there 

 was a Northerly wind on the American coast, and a Southerly wind at some 

 distance to the Eastward of that coast. This state of the wind, considered 

 in connection with Buys-Ballot's Law (page 113), requires that there should 

 be a trough of low pressure between two high pressures. Buchan's 

 Monthly Charts of Isobars,:]: giving the mean pressure over the globe, show 

 that the above is the case in the months of January and February. The 

 January chart shows the isobar of 30*2 over the American land, and again 

 over the sea just to the Northward of the N.E. Trades, and we know that 

 between these high pressures the hot Gulf Stream flows, which may weU 



♦ "American Journal of Science," 1876. 



t " A Discussion of the INIeteorology of the part of the North Atlantic lying North of 

 lat, 30° N. for the Eleven Days ending February 8th, 1870, by Captain Henry Toynbee. 



+ " The Mean Pressure of the Atmosphere and the Prevailing Winds over the Globe 

 xor bills Montns and for the Year." By A. Buchan, M.A., F.R.S.E. " Transactions of 

 the Royal Sociatv." Edinburgh, vol. xxv. 



