-August 26, 1920] 



NATURE 



837 



The occurrence of barytes in the upper parts of 

 lodes containinfj metallic sulphides is probably well 

 recognised, and postulates an infiltration of barium 

 chloride upwards during the formation of the lode 

 or downwards to meet the sulphates that are in solu- 

 tion. Mr. H. W. Greenwood suggests (Proc. Liver- 

 fKJol Geol. Soc, vol. xii., part 4, p. 355, 1920) that 

 the barytes which is common in the English Triassic 

 strata, and mainly found in the upper beds, 

 was derived from overlying Jurassic strata. The 

 source of an exceptional quantity of barium in the 

 Jurassic seas is not indicated. Might it not have 

 been brought into the Triassic pan-deposits from the 

 denudation of our Armorican lode-formations? 



In a general " Review of the Reptilian Fauna of 

 the Karroo System " (Trans. Geol. Soc. S. Africa, 

 vol. xxii., p. 13, iq2o) Mr. S. H. Haughton concludes 

 that the preservation of complete skeletons of Pareia- 

 saurians in the beds south of Prince Albert Road 

 station was determined by a rapid deposition of fine 

 mud or silt. In the discussion on this paper (Proc. 

 ibid., p. xli.) Dr. van Hoepen supported, by his 

 personal observations on the skeletons of various 

 genera, the view of entombment in swampy lakes 

 rather than, as Mr. Watson had suggested, in wind- 

 borne sand. Dr. du Toit stated that he was un- 

 willing to return to the old supposition of a general 

 Karroo lake in Lower Beaufort times, but he pic- 

 tured a surface "that became periodically inundated 

 and, at certain stages, semi-arid in climate." 



The present summer has so far experienced some 

 disturbing weather anomalies, the abnormal features 

 being chiefly the persistent low temperatures and the 

 frequent heavy rains. Some improvement has been 

 generally experienced during the present month owing 

 to the greater prevalence of anticyclonic conditions. 

 A disturbance, however, traversed the north of Ire- 

 land and the southern portion of Scotland on the 

 night of August 17 and the early part of August 18. 

 The storm area followed a track fairly due east, and 

 was preceded an3 accompanied by a heavy downpour 

 of rain which occasioned considerable damage in 

 Edinburgh and the surrounding neighbourhood. The 

 rainfall at Edinburgh for the twenty-four hours to 

 Wednesday morning was 3-1 in., and in twelve hours 

 the fall amounted to 2 in. At Leith the fall in twenty- 

 four hours was 284 in., and at Renfrew 280 in. A 

 subsidiary disturbance occasioned heavy rain in the 

 south of England, and at Falmouth the fall was 

 2-21 in. between 8 a.m. and 7 p.m. on August 18. 

 Very cool northerly winds spread over the country in 

 the rear of these disturbances. On the morning of 

 August 20 frost occurred on the ground in the open 

 in Scotland and in parts of England, whilst tn places 

 the thermometer in the screen fell to 36°. At Green- 

 wich the exposed thermometer registered 33° and in the 

 shade 41°, which was only 3° above the lowest figure 

 reached in August since 1841, 38° being recorded in 

 1864,. when the exposed thermometer fell to 27°. At 

 Kew it was the coldest August night since 1891, and 

 at Falmouth it was as cold as any time in August 

 during the last half-century. 

 NO. 2652, VOL. 105] 



Among recent pamphlets issued officially by the 

 Meteorological Oflice under the heading of Profes- 

 sional Notes is one by Mr. J. S. Dines entitled 

 " Methods of Computation for Pilot-balloon Ascents." 

 Without claiming to be exhaustive, this gives some 

 account of, at any rate, the better-known methods of 

 determining wind velocities at different heights. 

 Part i. deals with the most practised single-theodolite 

 ascents, and nine methods are described, including 

 those in general use by the military Meteorological 

 .Services of France, Italy, and the United States, partly 

 graphical and partly depending ujxin a special slide- 

 rule. The ideal method for open-air work discards the 

 graphical method so far as possible. Part ii., dealing 

 with double-theodolite ascents, gives six methods of 

 dealing with these, including, as does part i., the 

 Meteorological Office method, which depends entirely 

 on the slide-rule. Part iii., on balloon-tail, gives two 

 graphical methods besides the Meteorological Office 

 slide-rule plan. Perhaps more interesting than any of 

 these is the appendix dealing with various methods of 

 obtaining velocities at heights when cloud-sheets pre- 

 vent the observation of pilot-balloons. The smoke from 

 anti-aircraft shells set to explode at a given height 

 can be observed through a comparatively small break 

 in the cloud, and even when the cloud-sheet is quite 

 unbroken the position of bomb-bursts can be deter- 

 mined by soimd-ranging from the ground or bv 

 observation from an aeroplane. 



It was scarcely likely that proposals so far-reaching 

 in effect and importance as those put forward by the 

 Egyptian Ministry of Public Works for the extensive 

 development of the cultivable area of the valley of 

 the Nile by the construction of a dam and other irriga- 

 tion works should escape a large measure of hostile 

 criticism, and we have on several occasions alluded 

 to the attacks made by Sir William Willcocks on the 

 validity and trustworthiness of the data on which 

 the scheme is founded. These attacks, it will be 

 recalled, led to the appointment of a Special Inter- 

 national Commission of Inquiry, which has had the 

 projects under review. We have now received a copy 

 of a brochure issued by an independent Commission 

 of Native Egyptian Engineers, who take up an atti- 

 tude of strong and uncompromising opposition to the 

 official proposals on the grounds that there are 

 obvious inconsistencies in the fundamental calcula- 

 tions, and an evident tendency on the part of the 

 Technical Adviser to the Egyptian Government to 

 "adapt" his data to the requirements of the case. 

 The objectors state that they fear that any attempt 

 to cut off or decrease the supply of water and silt to 

 Egypt from the Blue Nile will be fraught with disas- 

 trous consequences, and they set out their arguments 

 in a series of sixteen criticisms of the official scheme. 

 An addendum by Dr. Mahgoub Sabitt, professor of 

 medical jurisprudence and toxicology at the Egyptian 

 University, advances reasons for considering the con- 

 struction of the proposed dqm likely to prove detri- 

 mental to public health. A protest is also entered 

 against the alleged secrecy in which the proposals 

 were prepared and formulated, and finally a call is 

 made for a mixed committee of native and foreign 



