50 REPORT — 1859. 



obliged to remain for weeks at a station, before getting a favourable opportunity to 

 observe some of their angles. 



Note. — From observations made on the subject of the above paper during the year 

 1859, the view from the vicinity of Aberdeen was found to be limited to the above- 

 mentioned distances on 128,47, 31, 41, 30, 76, and 12 days respectively. — Feb. 1860. 



On the Diurnal Variation of the Barometer. By T. Da vies. 

 The author examines the effect of the sun's heat on a column of air of the 

 height of the atmosphere about the torrid zone, where the heat is greatest, and the 

 days and nights nearly equal. The main phenomena of the diurnal variation are, 

 he finds, represented by this cause. The communication was illustrated by diagrams, 

 which showed two chief maxima and two lesser maxima, with the corresponding 

 intervening minima, at critical hours of the day. 



On Mild Winters in the British Isles. By Prof. Hennessy, F.R.S. 

 The author pointed out the circumstance that the meteorological observations made 

 during the late remarkably mild winter tended to confirm the law which he had already 

 announced in a letter to General Sabine, which appears in the * Proceedings of the 

 Royal Society ' for 1 858. This law is, that during mild winters the coast stations 

 exhibit an increase of temperature more than inland stations, and that the tempe- 

 rature on the west and south coasts approaches towards uniformity. In France, as 

 pointed out by M. Liais, the first part of this law is found to hold good, as evinced in 

 the comparative climatology of Cherbourg and Paris. Mr. Hennessy referred these 

 phenomena to an abnormal extension of heat-bearing currents across the Atlantic. 

 The prevaling westerly and southerly winds would, under such circumstances, transfer 

 to our shores a great portion of the warmth which they had received from contact 

 with the heated waters at remote portions of these currents ; for the condition 

 of the ocean bathing our shores, would be favourable to the preservation of such 

 warmth in the strata of air passing over its surface. From the greater stability of 

 such currents than those of the atmosphere, and from the important influence they 

 undoubtedly exercise upon our climate, he is led to infer that we are rapidly ap- 

 proaching a period when it may become possible to foretell whether the winter shall 

 be cold or warm by knowing the conditions of temperature and the movements of 

 currents in the Gulf of Mexico and the Atlantic during the summer and autumn. 



On the Distribution of Heat over the Sun's Surface. By J. J. Murphy. 



On the Aqueous Vapour of the Atmosphere. 

 By Rear-Admiral FitzRoy, F.R.S. 



In order to show why this subject was of urgent importance, the author gave a 

 brief description of the origin, nature, and objects of the Meteorological Department 

 of the Board of Trade, which was instituted to collect and publish meteorological 

 observations made at sea ; and explained that he now required the opinions of com- 

 petent authorities as to the best method of publishing a great accumulation of valu- 

 able observations. Referring especially to the division of opinions of some scientific 

 men on the question of aqueous vapour, and the reduction of barometrical observa- 

 tions, the Admiral quoted passages from the reports of Col. James and Prof. Patten, 

 printed in the third Number of ' Meteorological Papers' published by the Board of 

 Trade in 1858. Admiral FitzRoy then submitted to the President of the Section 

 that it would be desirable to elicit some authoritative opinions on the subject in 

 question, before he proceeded to other meteorological perplexities which he had in 

 reserve for another occasion. 



On Atmospheric Waves. By Rear-Admiral FitzRoy, F.R.S. 

 As so much has been said during the last few years about " atmospheric waves," 

 I would refer to them here. If wind veers round the compass in the course of two 

 or three days (more or less), or is many days in making a circuit — invariably, as it 



