373 



OIL FROM TOMATO WASTE. -In a recent article 

 on the waste products from some chemi-Ml industries, S. 

 Fachini refers to the possibility of economically recovering- oil 

 from the waste in the manufacture of tomato sauce. It had 

 already been proposed, with such an end in view, to subject the 

 crude material to a preliminary drying process, but it is now sug- 

 gested as more economical to agitate the waste with water, allow 

 the seeds to settle, remove the latter and transfer them to a centri- 

 fugal machine, where they can be freed from the greater part of 

 the adherent moisture. They are then to be dried, and the oil 

 recovered by pressing or extraction, the last traces of the volatile 

 solvent to be driven from the residue and from the oil by heated 

 carbon dioxide gas instead of steam. 



TRANSACTIONS OF SOCIETIES. 



South African Institute of Electrical Engineers. — Thursday, 

 March i6th : J. H. Rider, V.P.I.E.E., President, in the chair. — "Some 

 Aspects of Theory" : Sir W. H. Preece. The author emphasised the 

 value of correct theory in hastening progress by enabling the brain to 

 guide the hand. Viewing electricity as a form of energy, he briefly 

 discussed the motion of electric waves, and the application of Newton's 

 gravitation and Ampere's dynamic laws to electrons and atoms. — 

 "Troubles on overhead Power Lines"; C. W. R. Campbell. Amongst 

 the points specially referred to were the following : The decided in- 

 fluence of the geographical direction of the line ; the faulty material of 

 insulators, and the flashing over caused by lightning and, more 

 frequently, by birds; objects blown or thrown over the lines and guard 

 wires; the contraction of the line during cold weather; the wash out of 

 poles from soft ground during heavy rain or their being rendered 

 insecure by animals rubbing against them. 



Geological Society of South Africa.— Monday, March 20th : Dr. E. 

 T. Mellor, F.G.S., President, in the chair. — "Notes on the Steinkopf 

 Beds in Narnaqualand" : J. G. W. Leipoldt. A geological descrip- 

 tion of a series of stratified sedimentary rocks, north-west of the Mission 

 Station of Steinkopf, extending north and south for over 40 miles, and 

 from five to ten miles east and west. To these rocks, which differ in 

 character from the older formations of the north-west, the author 

 assigns the name of "Steinkopf Beds." — "Some structural features of 

 the Witwatersrand system on the Central Rand : with a note on the 

 Rietfontein Series" : Dr. E. T. Mellor. A system of strike faults 

 of considerable magnitude in the Lower Witwatersrand formation on 

 the Central Rand was described. The line of fault had a marked effect 

 on the apparent succession of beds in the Lower Witwatersrand Forma- 

 tion, and would also modify the apparent thickness of other beds on 

 the Central Rand. The author agreed that the Rietfontein Series 

 belongs to a formation unconformable to the Witwatersrand System. 

 "Petrological notes on the Kimberlite occurrences in the Pretoria 

 District" : Dr. P. A. Wagner. An account was given of the petro- 

 graphy of the rocks met with in occurrences of a basaltic Kimberlite in 

 ten localities in the Pretoria District ; observations were also recorded 

 descriptive of the passage from yellow to blue ground in the Premier 

 Mine, of four meg^scopically distinguishable varieties of blue ground, 

 and of inclusions In and later intrusions into the latter. Fusion, and 

 subsequent recrystallisation experiments on the highly serpentised blue 

 ground from the upper portions of the Premier Mine, in order to test 

 the possibility of thus obtaining a rock resembling fresh Kimberlite 

 were also described. 



