BY E. C. NOWELL. 



49 



influence upon the earth, but it is an influence of an altogether 

 different kind to the one which is implied by this popular 

 piece of weather delusion ; it is the influence which is so 

 grandly expressed in the diurnal roll of the tides of the sea, 

 and which is due to the inter-action of the lunar and terrestrial 

 mass." In regard to the tides the same writer tells us: "It 

 is the moon which is operative in bringing about the result, 

 and not the ' phases ' or appearance of the moon." 



But, we may ask, is not the distinction here drawn between 

 the moon herself and her " phases " rather one of words than 

 of things? If the moon's changes of position, which we call 

 her " phases," cause corresponding changes in the weather, 

 there certainly would be good reason for associating such 

 changes with the phases under which they occur, whether the 

 popular mode of stating the fact were strictly correct or not. 



Dr. Mann goes on to say : " Now, there can be no question 

 that the moon does produce a somewhat similar effect upon 

 the atmosphere to that which it exerts upon the sea. As it 

 goes round the earth, and as the earth whirls upon its axis in 

 front of the attendant orb, a tidal swell is called up in that 

 part of the atmosphere which is most immediately opposite 

 and nearest to the lunar mass ;* and this tidal wave in the_ air 

 "undoubtedly is accompanied by some change of physical 

 state which would involve alteration of pressure, and which 

 would be to that extent indicated by the barometer, and 

 would tend to produce movement in the air or wind, and such 

 weather change as is attendant upon wind. But all this, it 

 will be observed, has nothing whatever to do with the phases 

 or changes of the moon. The effect, whatever it may be, is 

 precisely the same whether the moon is new, or half 

 illuminated, or full. It is determined and measured only by 

 the revolution, distance, and mass of the moon, and by the 

 dimensions and rotation of the earth." But the inference is 

 drawn from certain observed facts " that the heat reflected 

 from the full moon does exert a palpable effect upon the 

 atmosphere, although it does not penetrate to the solid 

 surface of the earth ;" and Sir John Herschel is said to have 

 noticed " how very commonly the nights of the full moon at 

 the Cape of Good Hope were absolutely cloudless and clear ;" 

 and this observation, we are informed, is confirmed by the 

 experience of nearly nine years of the author of the article 

 from which I have quoted in the neighbourhood of Natal. 



Dr. Lardner, in his " Weather Prognostics " (Museum of 

 Science and Art, vol. I. p. 80), after reviewing the investiga- 

 tions of different persons on the subject of the moon's 



* One cannot help noticing the remarkable coincidence between the words of the 

 ancient poet already quoted, fratris radiis obnoxia Luna, and those ot tue 

 exponent of modern science. 



D 



