110 THK XI'J'ROGEX PROBLEM. 



suji, wliicli finds its field of iiftioii also to so large an extent 

 in the vegetable kingdom. 



Plants haA'e harnessed the sun, and are thus enabled to 

 bring about chemical processes and reactions of the most 

 unending variety and the most beautiful kind, compared with 

 which the methods of the laboratory are crude and unrefined. 

 By nourishing the plant within the soil from the boundless 

 stores of nitrogen in the air, we shall at least in one respect 

 effect tlie development of the land awaiting cultivation in this 

 country and give a spur to the utilisation of its real values. 

 Whether it will be possible to increase the potential of the 

 sun's energy, and thus obtain power of the intensity which is 

 usually associated with this word is for future iuA-estigation 

 and research. As is well known, serious attempts to solve 

 this problem have already been made. When it is achieved 

 South Africa will be rich indeed. 



LIST OF PAPEES READ AT THE SECTIOIs^AL 

 MEETINGS. 



Section A. — Astronomy, Mathematics, Physics, Meteo- 

 rology, Geodesy, vSurveying, Engineering, Architec- 

 ture AND Irrigation. 



WEDNESDAY, JULY 14, 1920. 



1. Presidential Address on " Recent Progress in Astronomy " bv 



H. E. Wood, M.Sc. 



TRUBSDAY, JULY 15. 



2. The effect of high temperature and altitude of Aerodrome in the 



taking off of Aeroplanes: P. G. Gundky, B.Sc, Ph.D. 



3. A short note on Einstein's planetary equation : W. N. Roseveare, 



M.A. 



4. Rainfall and barometric variation in Bulawavo : E. Goetz, S.J., 



MA. 



5. Note on a diagram showing the amount of available sunshine falling 



on a horizontal surface on any day of the year at a given place 

 and showing also the sun's elevation and its time of rising and 

 setting. J. T. Mokkisox, M.A., B.Sc. 



Section B. — ^Chemistry, Geology, Metallurgy, Miner.vlogy 

 AND Geography. 



THUBSDAY, JULY 15. 



1. Presidential Address on " Geology in relation to Mining " l)y 



F. P. Mennell, F.G.S., M.I.M.M. 



2. Bat Guano deposits of Rhodesia : E. V. Flack. 



3. Some further factors influencing the solubility of Phosphoric Oxide 



in mixed fertilisers containing superphosphates : E. V. Flack. 



4. The geological section between Bulawavo and the Victoria Falls: 



H. B. Maufe, B.A. 



5. Karroo rocks in the Mafungabusi, Southern Rhodesia: A. J. C. 



Molyneux, F.G.S. 



6. On the volumetric determination of Phosphoric Oxide: B. de C. 



MAIiCHAXD, B.A., D.Sc. 



