'NIK DKTKR M (NATION OF FAST KR DAY. 



179 



It so happens that the first visibility of the new moon is not a 

 matter of general importance to modern astronomers, and few 

 observations have been made with that end in view. Dr. J. K. 

 Fotheringham has, however, propounded a rough empirical rule, based 

 on the records of 76 observations (six being of the old moon), that 

 the new moon is never to be seen by the naked eye when its 

 angular distance from the sun is less than 12 degrees, and then 

 only when it is in the most favourable direction. 



An old moon was, however, observed (among the above 76) when 

 only 9'2 degrees from the rising sun and not in the most favourable 

 direction. Dr. Fotheringham, however, dismisses this observation 

 with the remark that it must not be considered, because the 

 atmosphere is clearer at dawn than at sunset. But every practical 

 astronomical observer knows that the clearness of the atmosphere 

 at sunset varies immensely on different evenings which are cloudless, 

 and this particularly affects the visibility of faintly illuminated 

 celestial objects near the horizon. 



Jerusalem is at a lower latitude than were the places at which the 

 76 observations were taken; consequently darkness comes on more 

 quickly after sunset, and faintly illuminated heavenly bodies are 

 more easily seen. Also it must be remembered that Jerusalem is 

 about 2,600 feet above the sea ; celestial objects near the horizon 

 can there be seen with greater clearness than from the lower levels 

 at which the 76 observations were taken, because there is a less 

 density of air to look through. 



On February 10, 1910, Mr. D. W. Horner, a well-known 

 observer, and others at Tonbridge, saw the new moon with the 

 naked eye at an angular distance of only about 10 degrees from the 

 setting sun, the direction not being very favourable. 



Visible Phase of the Moon," p. 530, by J. K. Fotheringham, M.A., D.Litt. ;; 

 also a paper on the same subject in The Journal of the British Astro- 

 nomical Association, May and June, 1911, by E. W. Maunder, F.R.A.S. 

 Also Journal of Theological Studies, "Astronomical Evidence for the: 

 Date of the Crucifixion," October, 1910, p. 120, by J. K. Fotheringham. 

 Various articles in The Churchman on the date of the Crucifixion, April,, 

 1910, to November, 1912, by Rev. D. R. Fotheringham, J. K. Fothering- 

 ham, E. W. Maunder, F.R.A.S., Lt.-Col. Mackinlay, and Mr. Bothamley. 

 Also The Observatory, April, 1911, p. 162, and The English Mechanic, 

 May 5, 1911, p. 308. Letters by D. W. Horner. 



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