Possible Lunar Injiuence npoii the Velocitij of the Wind at Kiwherley. 
293 
The whole range of velocilA is nearly 0 2 mile an hour, its relation to the 
whole range of pressure being 62 miles to 1 inch. 
(6) The results of the previous paragraph are emphasised in a com- 
parison between the mean perigee curves of Avind and pressure; and, 
besides, the XXIII asperity is strongly marked on the wind curve. 
(c) Just as the moon-rise maximum and the asperity at XXIII are 
faintly marked on the. pressure curve at apogee, so are the moon-rise 
minimum and the asperity of velocity. The turning-points on the apogee 
wind curve lag somewhat. 
((/) The noon perigee curve of velocity also shows a large general rise. 
The smoothing of the curve, however, has intruded a fall after XXIII. Had 
this been done with the pressure curve the values at XXIV and XXV would 
have been 1-0027 and '9998 instead of 1-0354 aiid 1-0070 respectively, and 
the asperity at XXIII would have been merged into the L.M.P. maximum, 
as it is in the case of the wind. 
(e) The slackening of velocity after the moon has crossed the meridian 
during midnight perigee corresponds to the large fall of pressure. The 
break in the fall of pressure at moonset which carries the minimum on to 
between XX and XXI is matched by the irregularity of velocity between 
XIX and XXI. 
(/) At "horizon " perigee the large general fall of velocity is marked, 
and it enliances the moonset minimum. The wind curve bears the same 
kind of relationship to the pressure curve in this case as it does in 
general.* 
(g) The small asperities of pressure in the nature of tiny maxima 
occurring near moonset are not represented in the velocities. 
Note. — In the diagram the ordinates of the pressure curve are taken at 
clock hours, tln^se of the wind apply to the middle of whole hours. 
The Tropical Month. 
As a matter of intei-est rather than in the expectation of obtaining any 
important relationships, the mean daily velocities have been compared with 
the mean daily pressures during 255 tropical months. The results, 
smoothed in threes, are shown in Table II, in which column 2 gives for 
periods of twenty-seven days (of which the fourteenth day is that of the 
moon's greatest south declination) the mean barometric pressure of each 
day in inches, and column 3 the corresponding mean daily velocity of the 
wind. 
* Better analogies would probably be obtained from a comparison of (f) and (/) if 
each of the curves were to be subdivided into two, one giving particulars for the 
hours between II and X, and the other for the hours between XI\^ and XXII. A 
longer series of observations would be required for the discussion however. 
