52 report — 1859. 



paper, representing the oscillations of a barometer as the wind veers round the com- 

 pass, corresponds to a mechanical, wave-like undulation of the body of atmosphere, 

 is not proved. 



We may demur to it on these grounds. First, the curve so traced on paper 

 varies, not only with the barometer, but with the direction of the wind, which is inva- 

 riably accompanied by change of pressure, consequent on the greater or less action 

 of polar or equatorial current. 



Secondly, while the wind remains in one quarter, the curve or line, taken as that 

 of a wave, remains almost unvaried, except in consequence of altered strength of wind 

 or much rain, which have each a comparatively small effect. 



Thirdly, the lowest part of the curve (called the trough of the wave) always cor- 

 responds to the lowest barometer, or lightest air ; whereas it is the lightest air that 

 rises highest, as instanced at the equator ; and therefore the crest of an atmospheric 

 wave (so to speak) ought to be over the place of lowest barometer. 



Fourthly, aeronauts always find, and the upper clouds often show currents above, 

 very different from those below. These superposed and successive strata, in rapid cross 

 motion, must tend to destroy undulation. I am aware of what Sir John Herschel 

 has written on this subject (atmospheric waves) in his invaluable 'Essay on Meteor- 

 ology,' in the last edition of the Encyclopaedia Britannica ; but with the utmost de- 

 ference I submit, that his experiment— on the undulations transmitted through suc- 

 cessive (coloured) strata of fluids in a vessel — did not meet the case of fluid strata 

 moving horizontally, in various directions, across each other. 



That there are tidal waves in the atmosphere, caused by the sun and moon, ex- 

 periment has proved; but that they are very small has also been demonstrated. 

 This subject, however, has yet to be investigated, by means chiefly of the accurate 

 barometrical measures instituted and carried on by Government during late years, in 

 many parts of the world, and especially at sea. Such waves as these would follow 

 their causes — in periodic times — and not, in utter disregard of sun and moon, only 

 correspond to direction and strength of wind. 



Meteorological Observations made at Httggate, Yorkshire. 

 By the Rev. T. Rankin. 



This was a series of tables and observations on the most remarkable meteorolo- 

 gical phenomena observed during the year 1858-59 in Yorkshire, in continuation of 

 a similar contribution continued for many years by the same author. They in- 

 cluded observations with tables on barometer and thermometer, wet-bulb thermo- 

 meter, rain-gauge, winds, aurora, the comet, and other remarkable phenomena, such 

 as thunder-storms. ^^^^^^ 



On Tables of Rain registered at Georgetoivn, Demerara. 

 By P. Sandeman. 



These Tables were constructed with the view of ascertaining what relation, if any, 

 exists between the motion of the moon in declination and the state of the weather. 



The idea entertained was that the quantity of rain which fell during the time of 

 the moon's motion in declination, changing from north to south in the northern 

 hemisphere, and from south to north in the southern hemisphere, would be found in 

 excess over the quantitj' which fell during the time the moon is crossing the equator 

 from south to north, or from north to south. The abstract Table No. 5 shows this 

 to be the case in four years out often. In regard to the absolute amount of excess 

 over the ten years, the theory holds ; the excess when the moon is over the northern 

 hemisphere being 32 inches, and when it is over the southern hemisphere 31 •'J inches. 

 The conclusion of the paper exhibits some points of interest. The author remarked 

 that during the years in which the theory fails are to be noted the following pecu- 

 liarities : — The rains during 1849 were excessive, amounting to 127 inches ; it rained 

 almost all the year, reckoning from the preceding month of November. During 

 the months of May, June, and July of that year, nearly 60 inches fell. 



During the year 1851, the rain, instead of being confined as usual to certain months, 

 began to be more distributed over the year. In fact the rainy and dry seasons were 

 scarcely distinguishable. 



