LIGHTING OF INTERIORS. 325 



it is but little dearer than direct lighting-, if the latter is carried 

 out properly. We certainly obtain less illumination than in the 

 direct way, but the greater uniformity requires also a good deal 

 less ; and, the nearer artificial conditions approach more natural 

 ones, the greater is the resulting comfort. With properly diffused 

 artificial light, the eyesight of the human race would be materially 

 improved. 



The tests were carried out with conical opaque shades. The 

 results will, however, be little different with other shades, i.e., as 

 far as the average values are concerned, except as regards the 

 uniformity. The conical shape gives results slightlv better than 

 the holophane glass globe, which comes next in a set of six 

 different kinds of shades tested. 



ELECTROTECHNICAL COMMISSION— At the St. 



Louis Electrical Congress of 1904 the formation of an Interna- 

 tional Electrotechnical Commission was resolved on, and a preli- 

 minary meeting was held in London in 1906, when the Commission 

 was practically constituted, Lord Kelvin being elected its first Presi- 

 dent. The first Council meeting, held two years later, nominated 

 Prof. Elihu Thomson as President, and a full meeting of the 

 Commission is to take place at Turin during the latter half of 

 1911. Electrotechnical Committees have been established in 



sixteen countries, and in most cases these receive the financial 

 support of their respective Governments. In eight other countries, 

 including South Africa, similar committees are either in process 

 of formation or likelv to be formed. 



TRANSACTIONS OF SOCIETIES. 



South African Institute of Electrical Engineers.— Thursday, 

 February Qth : J. H. Rider, V.P.I.E.E., President, in the chair. — Pre- 

 sidential address: J. H. Rider. — The President briefly referred to 

 the aims, objects, and functions of the Institute. 



Geological Society of South Africa. — Monday, January 30th : 

 Prof. R. B. Young, M.A., B.Sc, F.R.S.E., F.G.S., President, in the 

 chair. — "The problem of the Rand banket," Presidential address : Prof. 

 R. B.Young. The banket is generally agreed to be a littoral marine 

 deposit, conspicuously affected by cementation since its deposition, sub- 

 jected to considerable strain, and influenced by numerous igneous in- 

 trusions. The presence and form of pyrite in the rock is difficult of 

 explanation, whether the placer or infiltration theory be adopted. In 

 any case it is probable that solution and reprecipitation of pyrite 

 throughout the rock had occurred. The gold in the rock assumes the 

 identical forms as in quartz veins. The carbon present is essentially 

 the same as anthracite, and has evidently been precipitated from some 

 liquid which had penetrated the rock's minutest cracks. In the author's 

 opinion that form of the infiltration theory which makes the precipita- 

 tion of the gold to depend on chemical rather than on physical causes is 

 to be preferred. 



