630 



TRANSACTIONS OF SOCIETIF.S. 



cciuipment. 'J he autlior went on to discuss the effect of drum protile, of 

 balance or tail ropes and of other factors on a choice between the two 

 systems. 



Wednrsda}- May 16th: L. B. Woodworth, A.M.I.E.E., Vice-President, 

 in the chair. — "A short description of the circle diagram '' : Prof. W. 

 Buchanan. An exposition of the properties of the circle diagram, pre- 

 pared as an introduction to the succeeding paper. — " A neiv construction 

 for the circle diagram'': G. M. Adams. The object of the author was to 

 introduce a new and simple method of con.structing the circle diagram, 

 from which the maximum power factor and the full load stator current 

 of an induction motor can easily be obtained. 



Thursday, June 21st: W. H. Perrow. M.I.E.E.. President, in the chair. 

 — ■■ Some modern developments in Roentgenology " : Dr. L. E. Ellis. 

 A short discriptlon was given of some of the most important t>pes of 

 apparatus used in the modern production of the Roentgen rays. The 

 principle and details of the Coolidge tube were also described, and the 

 author then proceeded to illustrate the medical and surgi'-a! a;)plications 

 of X rays, with special reference to tiie examination of the gastro- 

 intestinal tract. 



South Ai-juf.\N Socikiv ok Ciml. E.vgixkkk.^. — \\'ednesd;iy. |>me i.Uh : 

 R. W. Alenmuir M.I.C.E., President, in the chair.—" Possibilities of the 

 Wennncr's I 'alley IVafershed " : R. W. Menmuir. The sul)ject was 

 discussed with a view to tlie possibilities of a water supply for the City of 

 Capetown. In this connection tlie yield of the watershed and the cost Qf 

 constructing a dam and pipe line were compared with similar statistics in 

 respect of the Steenbrass catchment area. 



South African Institution of ExciXEiiks. — Saturdax. May 12th ; P>. 

 Price, AI.l.E.E., A.M.I.C.E.. President, in the chair. — " Cleaning condensor 

 tubes in their place zvith hydrochloric acid": G. M. Robertson. The 

 paper described an application of the method by the author for tlie removal 

 of calcareous scale. The condensor contained 4,725 brass tubes of five- 

 eighths of an inch inside diameter, and 14 feet long. 4,000 lbs. of acid of 

 f.150 sp. gr. were obtained. The coTidensor was liHed with water and 

 the water warmed. Circulating was iben started and the acid added to the 

 ivater at the rate of on? carboy every jo minutes, the circulation being 

 kepi up for about 16 hours in ail. Water was then circulated tlirough the 

 condensor for live or six liours to wash away the remaining acid. It was 

 estimated that H\ hours after cmnmencement of the operation i,26r lbs. of 

 scale had l)een dissolved, and .=; lbs. of coi)per from the tubes and ferrules, 

 out of a total weight ot ,^.^,'X)0 lbs. The condensor, , -if ter the operation, 

 was said to be as go(Kl as new. The cost oi acid and preparing the con- 

 densor was i50, and the work was stated to ba\e paid for itself in one 

 week by the saving in coal due to improved vacuum. — ■" h'riction of slime 

 pulp in pipes'': \i. J. Laschinger. Records were given of the results of 

 certain tests, and of the d.ila thus collected regarding the friction of slime 

 pulp in steel pipes, i'he matter is of iiuportance, since in nearly all reduc- 

 tion plant on the Rand the slime is handled in pulp form by means of 

 centrifugal pumps and piping. The slime pul]) consists of the finely com- 

 minuted i)articles of rock, vvliich will generally pass a screen of 200 meshes 

 per lineal inch, mixed with water in proportions varying from i to I of 

 solids to water, down to almost pure water. The friction head for slime 

 was found to be 1.3I per cent, less than for water. The power of a motor 

 driving a pump to elevate slime would ]i;i\e to be alxiut ,50 |)er cent, 

 greater than rcfpiired for water-punipin.g. 



Rov.\L Socll■:T^• of Sou in .Xi-imca. — Wednesday, June 20th: L. A. 

 Peringuey, D.Sc, E.E.S., F.Z.S., President, in the chair. — '' N ote on a case 

 of hermaphroditism" : II. V. Exner The author described a case of her- 

 Piai)hroditism occurring in a person of unsound mind, who had the 

 outward appearance of a Kaffir uirl. — " .V(;/(' on the genns Terfezia, a 

 intftfe from the Kalahari": I. P.. Pole Evans The trufifle Chocromyces. 



