5 GO Intelligence and Miscellaneous Articles, 



years, would gradually and not very slowly grow up to complete 

 eye-draughts of the moon, uuder the conditions of sunrise, mid- 

 day, and sunset ; and would themselves be again a starting-point 

 for the guidance of even closer scrutiny, with the greatest telescopes 

 and the sharpest eyes. 



20. Finally, my proposal, if allowed to make one, would be, that, 

 for the purpose of securing a series of satisfactory drawings of the 

 physical features of the moon, a six-inch achromatic, by Cooke, con- 

 structed for the purpose, be purchased out of the funds of the 

 Government Grant Committee, and held by a Board composed of 

 three Members of the Royal Society, to be nominated in the first 

 instance and the number afterwards filled up by the Council of the 

 Royal Society, in trust for the use of observers to be appointed by 

 the Board, each for a limited period,, and for a defined area of work : 

 the drawings and observations to be communicated, at least once a 

 year, to the Board. Cost of the instrument not to exceed 320 

 guineas, of a moveable house not to exceed ^850. 



LXXV. Intelligence and Miscellaneous Articles. 



A REMARKABLY EASY MODE OF APPROXIMATING TO THE CIR- 

 CUMFERENCE OF THE CIRCLE. BY S. M. DRACH, F.R.A.S., 

 F.R.G.S. 



To the Editors of the Philosophical Magazine and Journal. 



Gentlemen, 



117RITE down 



3-00000,0 

 — 800,0 



- 7 



A = 2-99199,3 

 + ^= + 14959,965 



B = 3-14159,265 

 + ^j= 29,91993 



VY 



+ 10^= 5,98398,6 



C =3-14159,26535,90391,6 



2A 



Sub.-^= -598,39860 



D = 3-14159,26535,89793,20140 

 A 

 Add it = 3740 



8-10 10 



E =3-14159,26535,89793,23880 

 True value 3- 14159,26535,89793,23846 



Error + -00000,00000,00000,00034 



