x. Proceedings. [Dece7nberi6th,\g\g. 



As it is desirable to know the accuracy of the result as 

 measured by the approximate error E = (A - R) 



«(R-G) (A" + G") - (A" - G") (R + G) 

 E " n{A n + G") - (A" - G") 



The two denominators are the same. 



Example. J^\ LetG=i. R= \ = ,1*4. 



7^96 

 Now let G=i'4. R=i*4 —7^0 — i'4i42i4. 



Professor Sydney Chapman, M.A., D.Sc, F.R.S., read a 

 paper by Mr. L. V. Meadowcroft, B.A., M.Sc, entitled: 

 "A discussion of the theorems of Lambert and Adams 

 on motion in elliptic and hyperbolic orbits." 



This paper is printed in full in the Memoirs. 



Mr. W. E. Alkins, M.Sc, read a paper entitled " Mor- 

 phogenesis of Reticularia tineata." 



This paper is printed in full in the Memoirs. 



General Meeting, December 16th, 1919. 



Sir Henry A. Miers, M.A., D.Sc, F.R.S. {President), 

 in the Chair. 



Dr. JOHN KERFOOT WOOD, F.C.S., F.I.C., Lecturer in Physical 

 Chemistry in the College of Technology, Manchester, and, 31, Roivan 

 Avenue, Brooklands, near Manchester ; Professor ARTHUR GEORGE 

 GREEN, M.Sc, (Leeds), F.R.S. , F.C.S., F.I.C, Research Chemist. 

 Nottoway C tough, Arthog Road, Hale, Cheshire; Mr. FRANK 

 LASSEY, B.Sc, Manager of the Manchester Branch, British Fibro- 

 cement Works, 414, Corn Exchange Buildings, Manchester, and Nor- 

 ther)! Lea, Northenden Road, Sale, Cheshire; Mr. WILLIS OPEN- 

 SHAW HOWARTH, M.Sc. (Mane), Lecturer in Botany in the Victoria 

 University of Manchester, and Fairlands, 39, Edge Lane, Chorlton- 

 cum-Hardy, Manchester ; and Professor O. T. JONES, M.A. (Cantab.), 

 D.Sc. (Wales), Professor of Geology in the Victoria University of 

 Manchester, The University, Manchester ; were elected Ordinary 

 Members of the Society. 



Ordinary Meeting, December 16th, 1919. 



Sir Henry A. Miers, M.A., D.Sc, F.R.S. {President), 

 in the Chair. 



Professor F. E.Weiss, D.Sc, F.R.S., F.L.S., exhibited and 

 made a few remarks on a green jade charm made by natives 

 of New Zealand. 



