TKA.NSACTIONS OF .sOt '] l':TTi::S. 381 



in spite of the increase of prices, the rise in prices being merely demon- 

 strative of a still bigger advance in tlic values of general commodities. 



Wednesday, September iitli: W. Elsdon-Dew. M.I.E.E., Vice-Presi- 

 dent, in the chair. — ''Short note on the manufacture of a Babcock and 

 Wilcox feed xvater regulator '' : D. Heslop. The Victofia Falls and 

 Transvaal Power Company decided to instal Babcock and Wilcox feed 

 water regulators on a number of their boilers, and as it was practicaelly 

 impossible to obtain delivery of tliese from overseas, it was decided to 

 make them locally at the company's Rosherville workshops. The float 

 type regulator had been found to be vastly superior to the thermo type, 

 and it was therefore decided to manufacture and instal this type. The 

 nature and details of manufacture uf the appliance were described. — 

 "Shop organisation: a simple scheme" : VV. E. John. An outline sketch 

 of a scheme for the organisation of a modern factory and, by way of 

 illustration, of a factory producing aeroplanes- 

 Wednesday, November i^tb: C. D. Leslie. President in the chair — . 

 " Hydraulic prospecting at the Rooiberg Tin Mines" : E. R. Schoch The 

 geological formations at Rooiberg have been classified as the Rooiberg 

 Series, belonging to the lower division of the Waterberg System. They 

 consist of sandstones, quartzitcs. and beds of shales. The cassiterite, 

 occurring in the form of veins and lodes in the sandstone and ([uartzites, 

 has, bj' the disintegrating tendency of the lodes and of the country rock, 

 been disseminated in the thick layer of sand which covers a large area, 

 and from which the tin may be profitably extracted. The method of 

 surface prospecting, by means of hydraulic jets or monitors, lias hitherto 

 been applied only where water is plentiful, and the area to be prospected 

 has a steep slope, along which the tailings can be automatically run off to 

 valleys lower down. The author described the method inaugurated at 

 Rooiberg as the first attempt to use this process on practically level 

 ground, with artificially conserved return water. — "Hammer drills: their 

 history, design, and operation. Part /"; H. S. Potter- The paper illus- 

 trated some of the more prominent machines on which most of the 

 successful hammer-drills are based in one or more details of their dcsigii 



Rov.\L Society of South Afric.x. — Wednesday, April 17th : Prof. 

 J. D. F. Gilchrist, M.A., D.Sc, Ph-.D.. F.L.S.. C.M.Z.S., President, in the 

 chair. — "Luminosity i>i a South African Earthworm and its origin": 

 Prof. J. D. F. Gilchrist. Luminous earthworms are found on the slopes 

 of Table Mountain. The luminosity proceeds from a discharge from the 

 mouth and anus, which consists of cells heavily laden with inclusions of 

 different kinds. The smaller inclusions consist of a substance allied to fat, 

 by the oxidation of which the light is produced. The cells arise from the 

 body cavity, and are discharged into the anterior and fjosterior parts of the 

 alimentarv canal by definite communications.—'' .V.i/r o;; the Adjugate of 

 Becout's eliminant of two binary quantics": Sir T'. Muir. — "On the 

 genera Diplocystis and Broomeia " : L R. Pole Evans and A- M. 

 Bottomley Some specimens of Diplocystis have recently been obtained 

 from Portuguese East Africa, the first recorded African occurrence of the 

 genus. The African material is not identical with that from Cuba, and 

 the authors describe it as Diplocystis Junodii n. sp. — " South African 

 Perisporiucecc //. Revis'wnal Notes '' : Dr. Ethel M. Doidge. A revision, 

 due to work on a number of fresh collections of South African Perisporia- 

 cex, of a previous communication on the subect by the author. — " Fresh 

 water snails as a cause of parasitic diseases ' : Dr. F. G. Cawstcn. 



The author described a number of snails collected In' him from various 

 districts in South Africa, and found to be infested with the cercarial stages 

 of the various trematode worms. — " Colour and chemical constitution : 

 part IV. The remaining phthaleins" : Dr. J- Moir The absorption- 

 spectra of complex phthaleins were described, these l)eing partly duplex 

 compounds of the phenol-anthrol type and partly of a new class derived 

 from thj'moylbenzoic acid. 



