August 23, 1894] 



NA TURB 



419 



is one point about the figures that I should like to mention. 

 No results were calculated till long after the completion of the 

 last experiment. Had I known how the figures were coming out, 

 it would have been impossible to have been biassed in taking the 

 periods and deflections. Even the calculating boys could not 

 have discovered whether the observed elongations were such as 

 would give a definite point of rest. I made my observations, 

 and the figure; were copied at once in ink into the books, where 

 afterwards they left my hands and were ground out by the cal- 

 culating machine. The agreement, such as it is, between my 

 results is therefore in no way the effect of bias, for I had no 

 notion till last May what they would be. 



escape from that perpetual comnand to come bick to my work 

 in London ; so I must then leave it, feeling suri that the next 

 step can only be made by my methods, but by some one more 

 blest in this world than myself. 



SCIENCE IN THE MAGAZINES. 



TN the August magazines received by us, science is but poorly 

 represented. A brief mention of the more important 

 articles will therefore be sufficient this month. 



Mr. Benjamin Kidd's work on " Social Evolution " has fur- 



My conclusion is that the force with which two spheres weigh- 

 ing a gramme each, with their centres i centimetre apart, attract 

 one another, is 66576 x 10"' dynes, and that the mean density 

 of the earth is 5-5270 times that of water. 



It is evident, from what I have already said, that this work is 

 of more than one-man power. Of necessity I am under obliga- 

 tions in many quarters. In the first place, the Department of 

 Science and .\rt have made it possible for me to carry ou' the ex- 

 periment by enabling me to make use of apparatus of my own 

 design. This belongs to the Science Museum, where I hope 

 in time to set it up so that visitors who are interested may ob- 

 serve for themselves the gravitational attraction between small 

 masses. Prof. Clifton, as I have already stated, has given me 

 undisturbed possession of his best observing room, his only good 

 underground room, for the last four years. The late Prof. 

 Pritchard lent me an astronomical clock. Prof. Viriamu Jones 

 enabled me to calibrate the small glass scale on his Whitworth 

 measuring machine ; and Mr. Chaney did the same for my 

 weights. I would especially refer to the pains that were taken 

 by Mr. Pye, of the Cambridge Scientific Instrument Company, 

 to carry out every detail as I wished it, and to the highly skilled 

 work of Mr. Colebrook, to which I have already referred. 

 Finally, I am under great obligations to Mr. Starling, of the 

 Royal College of Science, who performed the necessarily tedious 

 calculations. 



In conclusion, I have only to say that while I have during 

 the last five years steadily and persistently pursued this one object 

 with the fixed determination to carry it through at any cost, in 

 spite ofany opposition of circumstance, knowing that by my dis- 

 covery of the value of the quartz fibre, and my development of the 

 design of this apparatus, I had, for the first time, made it pos- 

 sible to obtain the value of Newton's Constant with a degree of 

 accuracy as great .as that with which electrical and magnetic 

 units are known, though I have up to the present succeeded to 

 an extent which is greater, I believe, than was expected of me, 

 I am not yet entirely satisfied. I hope to make one more eflfort 

 this autumn, but the conditions under which I have to work are 

 too difficult ; I cannot make the prolonged series of experiments 

 in a spot remote from railways or human disturbance ; I cannot 



nished material for much criticism. In the National Review 

 Mr. Francis Gallon, F. R.S., discusses the part of religion in 

 human evolution as set down in the book ; and Mr. Kidd adds 

 a short note on the opinions expressed in the article. The 

 same magazine contains a paper on " Sleeplessness " by Mr. A. 

 Symons Eccles, and one on "Colliery Explosions and Coal 

 Dust, " by Mr. W. N. Atkinson. ti An experience of fifteen 

 years in investigating explosions in coal-mines has led him to 

 believe that "coal dust has been the ctiief, or only, agent in 

 all recent widespread colliery explosions." It is regretted that 

 "no experiments have been made on a scale large enough to 

 yield visual demonstration of the effect of an explosion of coal- 

 dust, under conditions approximating as closely as possible to 

 those existing in mines. "The nearest approach to such experi- 

 ments in this country were those recently made by Mr. H. 

 Hall, H.M. Inspector of Mines, in an oil pit shaft fifty yards 

 deep. The length of such a shaft is insutTicient to develop the 

 whole force of a coal-dust explosion, and the conditions under 

 which the explosions or ignitions took place were necessarily 

 dififerent from those obtaining in the practical working of mines, 

 rhese experiments, however, are valuable, as demonstrating 

 that the dust ordinarily existing in a great number of mines 

 (not particular exceptional coal-dusts) are capable of propa- 

 gating flame to the full limits admitted by the conditions of the 

 experiments." 



-\ p-^ychological paper, entitled " How We Think of Tones 

 and Music," is contributed to the Contemporary by Mr. R. 

 Wallaschek. Mr. Andrew Lang tilts at Prof. Huxley's treat- 

 ment of the Bible story of Saul and the Witch of Endor " as a 

 piece of evidence bearing on an important anthropological 

 problem," and treats the matter from a less scientific point of 

 view. 



Eight recent books on Iceland furnish the subject of an 

 interesting account of the island in the Quarterly Review (No. 

 357). The same publication contains a long article on 

 " Forestry," in the course of which the author says that the 

 three great faults noticeable in the treatment of woods in Great 

 Britain are : (l) Discrimination has seldom been shown with 

 regard to the choice of the kinds of trees for given soils and 



NO. 1295, VOL. 50] 



