TKiiNSACTlONS OF SfiCTtON A, t)2& 



at 10 A.Jt. 6f January 9, 1896, and 27758 inches at 2.b0 p.m. 6f December 8, 

 1886 — a range of 3-262 inches, or rather more than 3^ inches. 



In conclusion the author submitted that the facts put forward in his paper 

 prove that, within the past six centuries at all events, no appreciable change has 

 taken place in the climate of the British Isles. There is not a scintilla Of 

 evidence to show that any such change has talcen place in the past or is likely to 

 take place in the future. 



2. A Comparison of the Changes in the Temperature of the Waters of 

 the North Atlantic, and in the Strength of the Trade Winds. By 

 Commander M. W. C. Hepworth, C.B., R.N.R. 



In order to confine that portion of the inquiry which relates to the trade winds 

 within manageable limits, two representative areas were selected for examina- 

 tion. One of these lies well within the region of the north-east trade wind, and 

 covers an area of 1,000,000 square miles ; the other is in the heart of the south- 

 east trade wind, and covers an area of 1,380,000 square miles. For the former 

 homogeneous averages for a period of five years only are available ; but for the 

 latter the results of four hourly observations, extending over a period of forty-five 

 years, have been utilised for estimating normal conditions. Judged by the five 

 years' averages, the north-east trade is strongest in April (13'5 statute miles 

 per hour); relatively strong in February (13 miles); in March (12-6 miles); 

 and in May (12'4 miles). It then rapidly declines in strength until August, when 

 its velocitv is only 82 miles per hour. It is lightest (7'4 miles) in iSeptember. 

 From Octooer its strength increases until February. According to the average 

 results obtained for the forty-five years' period mentioned, the south-east trade is 

 strongest (15'5 miles per hour) in February; relatively strong (15 miles) in 

 April and November ; also in March and December (14-9 miles). It is at about 

 its average strength for the year (14'7 miles) in January, August, and October. 

 In May it is lightest (13'7 miles), and from that month gradually increases, and 

 is again at its average strength for the year in August. It declines to 14'6 miles 

 in September. 



To represent the Morth Atlantic in a comparison of the changes taking place 

 in the surface temperature of that ocean two zones were selected — the one lying 

 between Florida Strait and Valencia, and the other between that Strait and 

 Cape Race. Average results, based on observations extending over a long series 

 of years, showed that the temperature of the surface water is lower in February, 

 March, and April than during any other period of the year, and is lowest in 

 March. It is relatively low, as compared with any other months than the above, 

 in January, May, and December, and of these months January has the lowest mean 

 surface temperature, and May the highest. The surface temperature is relatively 

 high in June, October, and November ; highest as regards those months in October, 

 lowest in November. It is higher in July, August, and September than during 

 any other period of the year; highest of all in August, not quite so high in July 

 as in September, in the Florida Strait to Valencia zone ; but in the Florida Strait 

 to Cape llace zone the mean is found to be the same in these two months. A com- 

 parison between results of Atlantic trade-wind velocity in each of the years 

 J 902-7 and those of North Atlantic surface temperatuiesfor the same period "leads 

 to the belief that a relation may be traced between departures from the mean 

 in the velocities of the trades in any one year and deviations from normal in the 

 average distribution of surface temperature in the North Atlantic in the year 

 following. Further, there is some evidence to prove that departures from the 

 average strength of the two trades during a series of months, and at times during 

 even so short a period as a month, are roughly reflected in deviations from normal 

 in the average distribution of surface temperature in the North Atlantic in the 

 corresponding series of months, or month, as the case may be, of the succeeding 

 year, notwithstanding the many causes affecting the temperature of the surface 

 water, which must tend to mask the appearance of any such connection. 



Jtlarge number of tables and diagrams accompanied the piper. 



1908. S s 



