322 



NOTES AND QUERIES. 



[No. 205. 



cipal conclusions to which scientific observations 

 tend, on this matter, may be pointed out without 

 perhaps encroaching too much on the space of 

 " N. & Q." 



Luke Howard, of Ackworth, several years ago, 

 concluded, from a series of elaborate observations, 

 extending over many years, that the moon exerted 

 a distinct influence on atmospheric pressure : and 

 Col. Sabine has more recently shown, from observ- 

 ations made at the British Magnetical and Meteor- 

 ological Observatory at St. Helena since 1842 — 

 " That the attraction of the moon causes the mercury 

 in the barometer to stand, on the average, '004 of an 

 English inch higher when the moon is on the meridian 

 above or below the pole, than when she is six hours 

 distant from the meridian." — Cosmos, vol. i. note 381, 

 (author, trans.); Phil. Trajis., 1847, art. v. 



Luke Howard farther gives cogent reasons, 

 from his tabulated observations, for the conclusion 

 that the moon has an appreciable effect upon the 

 weather, exerted through the influence of its at- 

 traction on the course and direction of the winds, 

 upon which it acts as a marked disturbing cause ; 

 and through them it affects the local distribution 

 of temperature, and the density of the atmosphere. 

 There is no constant agreement between the phases 

 of the moon and certain states of the weather ; but 

 an apparent connexion is not unfrequently ob- 

 served, due to the prevalence of certain winds, 

 which would satisfactorily account for the origin 

 and persistence of the popular belief: for, "it is 

 the peculiar and perpetual error of the human 

 understanding to be more moved and excited by 

 affirmatives than negatives" (Nov. Org.^ Aph. 46.). 

 For example, in 1807, "not a twentieth part of 

 the rain of the year fell in that quarter of the 

 whole space, which occurred under the influence 

 of the moon at full " {Lectures on Meteorology, by 

 L. Howard, 1837, p. 81.). In 1808, however, this 

 phase lost this character completely. 



A more marked relation is found between the 

 state of the weather and the declination of the 

 moon : for — 



" It would appear, that while the moon is far south of 

 the equator, there falls but a moderate quantity of rain 

 with us ; that while she is crossing the equator to- 

 wards tiiese latitudes, our rain increases ; that the 

 greatest depth of rain falls, with us, in the week in 

 which she is in the full north declination, or most j 

 nearly vertical to these latitudes ; and that during her ! 

 return over the equator to the south, the rain is re- 

 duced to its minimum quantity. And this distribution 

 obtains in very nearly the same proportions both in an ex- 

 tremely dry and in an extremely wet season." — Climate of 

 London, by L. Howard, vol. ii. p. 251., 1820. 



Still more recently, Luke Howard has summed 

 up the labours of his life on this subject, and he 

 writes : 



" We have, I think, evidence of a great tidal wave, 

 or swell in the atmosphere, caused by the moon's attrac- 



tion, preceding her in her approach to us, and follow- 

 ing slowly as she departs from these latitudes. Were 

 the atmosphere a calm fluid ocean of air of uniform 

 temperature, this tide would be manifested with as 

 great regularity as those of the ocean of waters. But 

 the currents uniformly kept up by the sun's varying 

 influence effectually prevent this, and so complicate 

 the problem. 



" There is also manifest in the lunar influence a 

 gradation of effects, which is here sliown, as it is found 

 to operate through a cycle of eighteen years. In these 

 the mean weight of our atmosphere increases through 

 the forepart of the period ; and having kept for a year 

 at the maximum it has attained, decreases again through 

 the remaining years to a minimum ; about which there 

 seems to be a fluctuation, before the mean begins to 

 rise again." — " On a Cycle of Eighteen Years in the 

 Height of the Barometer" (Papers on Meteorology, 

 Part 11. ; Phil. Trans., 1841, Part II.). 



It is satisfactory to all interested in this matter 

 to know that " the incontestable action of our 

 satellite on atmospheric pressure, aqueous preci- 

 pitations, and the dispersion of clouds, will be 

 treated in the latter and purely telluric portion of 

 the Cosmos" (vol. iii. p. 368., and note 596, where 

 an interesting illustration is given of the effects 

 of the radiation of heat from the moon in the 

 upper strata of our atmosphere). 



Jno. N. Radcliffe. 



Dewsbury. 



Not being quite satisfied with Mk. Inglebt's 

 answer to W. W.'s Query, I beg to refer inquirers 

 to the Nautical Magazine for July, 1850, and three 

 subsequent months, in which will be found a 

 translation by Commander L. G. Heath, R.N., of 

 a paper published by M. Arago in the Annuaire du 

 Bureau des Longitudes for the year 1833, entitled 

 " Does the Moon exercise any appreciable In^ 

 fluence on our Atmosphere ?" This treatise enters 

 fully into the subject, and gives the results of 

 several courses of experiments extending over 

 many years ; which go to prove that in Germany, 

 at all events, there is more rain during the waxing 

 than during the waning moon. Several popular 

 errors are shown to have arisen in the belief that 

 certain appearances in the moon, really the effect 

 of peculiar states of the atmosphere, were the 

 cause of such atmospheric peculiarities ; but we 

 ai'e allowed some ground for supposing that this 

 "vulgar error" may have some foundation in 

 " vulgar truth." G. William Sktring. 



LATIN RIDDLE. 



(Vol. vlii., p. 243.) 



The enigma of Aulus Gellius (Nodes Atticce, 

 lib. xii. cap. vi.), though transmitted to us in a 

 corrupt form, is solved at once by the story men- 

 tioned by Livy (lib. i. cap. Iv.). When Tarquinius 



