March 3, 192 1] 



NATURE 



23 



service. The greater consideration given to science 

 by the Government is an encouragement to the 

 coming generation of chemists to follow a career of 

 essential and vital importance to the needs of the 

 country. Sir Herbert Jackson added that it would 

 probably be regarded as desirable at the present 

 moment for the council of the institute, without 

 taking part in politics, to give expression to its views 

 on the grave importance of maintaining in this country 

 industries on which not only the future development 

 of our chemical industry and many allied industries 

 depends, but also the outlook of a very large number 

 of students of chemistry who are now in course 

 of training. The institute is entrusted by its charter 

 with securing the supply of well-trained chemists, but 

 unless a great chemical industry is maintained there 

 Avill be a very f>oor prospect for them. Mr. A. 

 Chaston Chapman succeeds Sir Herbert Jackson as 

 president of the institute. 



The dry weather experienced recently is occasion- 

 ing a suspicion in some quarters that the wet years 

 we have had may be followed by a period of drought. 

 This is naturally of importance in London and largely 

 populated centres. It is customary now to compare 

 rainfall results with the new normals for the thirty- 

 five vears 1881 to 19 15. Taking Greenwich observations 

 for means of comparison, the annual results for the 

 last ten years show an excess of rain in seven years on 

 the thirty-five years' average (2350 in.) and a deficiency 

 in three years. Other stations in the Thames Valley 

 generally support these results. The total rainfall at 

 Greenwich for the ten years was 254-25 in. Looking 

 at the Greenwich results for the last hundred years, 

 the heaviest rainfall in ten years seems to have 

 occurred in 1872 to 188 1, when there were seven years 

 ■with an excess, and three years with a deficiency, on 

 the hundred years' normal (24-41 in.). The total rain- 

 fall for the ten years was 26842 in. This was followed 

 by a dry period continuing approximately for twenty 

 years, from 1883 to 1902, during which there were 

 seventeen years with a deficiency, and only three 

 years with an excess, of rainfall. This single instance 

 affords probably little proof for future guidance. The 

 admirable Monthly Reports published by the Thames 

 Conservancy and the Monthly Maps of the Thames 

 Valley rainfall published by the Meteorological Office 

 would afford better and more valuable data for 

 inquiry, especially in connection with the water-supply 

 for London. 



In a discussion on "The Use of Light as an Aid 

 to Publicity " before the Illuminating Engineering 

 Society on February 24 attention was directed 

 to the indiscriminate use of bright lights in shop- 

 windows and for illuminated signs, and the need 

 for some form of co-ordination of such displays was 

 emphasised. It was also remarked that the lighting 

 of exhibitions, even those devoted to technical or 

 scientific processes, is usually executed in a very crude 

 manner without any scientific and organised plan. 

 The use of light for directing attention to objects and 

 revealing them to observers involves interesting 

 optical problems, some of which were illustrated by 

 a variety of luminous signs exhibited at the meeting. 

 There was general agreement that the best effect is 

 NO. 2679, VOL. 107] 



secured by adopting methods similar to those used in 

 lighting the stage of a theatre, i.e. by concealing the 

 actual light-sources from view. Capt. E. Stroud 

 showed photographs of a number of shop-windows 

 thus illuminated, and Mr. E. C. Leachman, who read 

 a paper on illuminated signs, exhibited some striking 

 pictorial transparency effects. A feature of these was 

 the use of a new method of depositing colours on 

 specially prepared linen, by the aid of which good 

 transparency of the coloured surfaces, high luminosity, 

 and vivid contrasts of light and shade were obtained. 

 It was remarked that the device of illuminating a 

 translucent picture from behind opened up new possi- 

 bilities in art, as painted pictures lighted in the usual 

 way from the front apjjear flat in comparison. Other 

 forms of signs made use of ingenious colour effects. 

 One of the most interesting devices was the sign 

 shown by Mr. E. T. Ruthven Murray, in which light is 

 distributed throughout the interior of a sheet of plate- 

 glass by total internal reflection, so that white letters 

 stencilled on the back appear strikingly illuminated, 

 the source of light, a tubular lamp, being completely 

 concealed from view. 



The publication of the first number of the 

 Antiquaries' Journal makes a new departure in the 

 history of the Society of Antiquaries, an attempt to 

 bring before a wider public the results of its inves- 

 tigations, which have hitherto lain buried for many 

 readers in the long series of its Proceedings and 

 " Archaeologia. " The character of this the first 

 example of the new publication ensures its success. 

 Perhaps the most important paper is the interim 

 report by Lt.-Col. W. Hawley on his excavations at 

 Stonehenge conducted during the work undertaken 

 for the preservation of the monument by H.M. 

 Office of Works. Full details of the results of the 

 digging required for the re-erection of some of the 

 monoliths are given, but in the absence of a scientific 

 commentary these may be regarded only as material 

 for examination by experts. The most interesting 

 new points are the excavation of the pits marked on 

 Aubrey's map of 1606 and the statement by Dr. H. H. 

 Thomas, Petrographer to H.M. Geological Survey, 

 who has arrived at the important conclusion that with 

 regard to the majority of the blue stones " their 

 ultimate source lay in the Prescelly Mountains and 

 in the boulder-strewn area to the immediate south- 

 east. All possible proximate sources, however, must, 

 of course, be investigated, but he felt that the idea 

 of Pembrokeshire boulders being carefully selected 

 from practically all other rocks, and stranded on the 

 high ground of Salisbury Plain by glacial action, 

 was contrary to all sound geological reasoning ; and 

 that such an assemblage of stones, of which so many 

 were of the same type, pointed to human selection 

 and conveyance from a distance." 



The Journal of the Royal Society of Arts for 

 January 28 contains a paper by Dr. C. S. Myers on 

 industrial fatigue. No satisfactory definition or test 

 of industrial fatigue is known, though various sug- 

 gested methods are discussed. Dr. Myers analyses 

 the work curve, and shows that it is compounded of 

 at least five different factors — fatigue, practice, incite- 



