2><(> TRANS. \CTIO.VS OF S(i( I i-.TI i;S. 



Saturdax. X<i\cml)er i^tli : W . Ingham, .M.I.C.E.. M.I.M.H. President, 

 in tlu' chair. — " J o' amirsbiir^ Tox^n Hall": W. HaTwke. A general 



descrii)tion uf tlie building was given, including particularly the Selborne 

 Hall, on the hrst flt:()r, an apartment of gift. X •47ft. and 31ft. high. 

 Flatpan stone from the Orange h'ree State was employed for the facades, 

 and in all approximately 120,000 cnh ft. of stone, and about tive million 

 bricks were used. General constructional details were given, as well as 

 an account of the more important steel-work items in the building. 



.Saturday, December nth: W, Ingham, M.I.C.E.. M.I.M.E., President, 

 in the chair. — " Ihc relative efficiencies of blasting irdatiitc and gelignite 

 as used in hand drill slo/^es in tie (/old mines uf the Rand": W. S. 

 Simpson. The paper coni])riscd an account of experimental work 



carried out on behalf of the \ ogelstruis Estates and Gold INIines. Ltd. In 

 two stopes of entirelv different character, blasting gelatine proved 25 pt?r 

 cent, more efficient than gelignite as an ore breaker. The relative efficien- 

 cies of the explosives agree closely with the comparative ballistic strengths 

 determined by the ballistic pendulum method. Forty per cent ligdyn as a 

 primer largely reduces the efficiency of gelatine, and probably also of 

 gelignite. Blasting gelatine gives greater efficiency with No. 8 than with 

 Xo. 6 detonators. 



Royal Soiiktv ov South Africa. — Wednesday. October 20: 

 L. A. Peringuev, D.Sc. F.E.S., F.Z.S., President in the chair. 

 — "A South 'African sl^ecies of Pelodrilus" : Prof. E. T- Goddard 

 and C. S. Grobbelaar. The specimens described coustituttj the 

 first recorded occurrence of the genus Pelodrilus in South Africa, 

 and were obtained from Sneeuwkop. near Wellington, at an alti- 

 tude of 4,500 feet. The distribution of the genus has hitherto been 

 restricted to the .\ntarctic region. — "Preliminary ncte on ancient Iinnian 

 sf^Uill remains from the Traiis-<val " : S. H. Haughton. Skull remains 

 found at Boskop. Transvaal, and the maimer of their occurrence were 

 described. The remains consist of the greater part of the skull-cap, a 

 temporal lione. and a portion of the lower jaw. The skull-cap is the 

 longest known, with the exception of that of La Chapelle-aux-Saints. Its 

 .greatest affinities arc with the skulk of the Cro-Magnon type. The fore- 

 head and anterior half of the skull agree with the Cro-Magnon and. 

 Bantu types, tind net at all with the Xeanderthal. The lower jaw is com- 

 paratively small and akin in character to that of the Bantu or Bushman type. 

 — '■ The Elastic Arch continuous oier several spans, capable only of small 

 rotary motions at the supports" : A. N.Henderson. — " Ttie Heating Co- 

 efficients of Rheostats and the calculation of Resistances for currents of 

 short and moderate durati'.m" : Prof. H. Bohle. — "Further Magnetic 

 Ob->erxations in South Africa during the years 1Q14-1915": Prof. J. C. 

 Beattie. The declination, dip and horizontal intensit3- were given for 27 

 st.itiiins, including two repeat stations in the Free State, Transvaal, and 

 Cape Provinces. — " True Isogonics and Isoclinals for South Africa for 

 the Llpocli 1st July. 1913 " : Prof. J. C. Beattie. The results at about 700 

 stations have been reduced to the epoch from observations at about 40 

 repeat stations fairly distributed over the greater part of the region. The 

 westerly declination has decreased in the ten years 1903-1913 by about l| 

 degrees in the west, and 2 degrees in the east. In the same period the 

 southerly dip has increased by approximately I degree in the east and i^ 

 degrees in tlie west.- — " Descriptions of some neiv Aloes from the Trans- 

 vaal " : I. B Pole-Evans. The author described the following six new 

 species of Aloes: — A. vereciinda, A. Simii. A. Barbertoniae. A. petricola, 

 A. sessilifolia, and A. Thorncroftii. — "A nczv Harmonic Analyser": Prof. 

 J. T. Morrison. In many physical researches, especially in meteorology, 

 it is necessary to enquire whether a fluctuating quantity, such as atmos- 

 pheric pressure, daily or monthly rainfall and the like, shows signs of 

 regular periodic variations, and the necessary operations are performed 

 mechanically bj^ the harmonic analyser described. 



South African Society of Civil Engixeers. — Wednesday. September 

 8th: R. W. Menmuir. A. M.I.C.E., Vice-President, in the chair —" /^!>/f r- 

 maritchurg-Riet Spruit Deviation, Natal Main Line " : D. Wilson. An 



