698 



NATURE 



[May 27, 1922 



Calendar of Industrial Pioneers. 



May 28, 1 83 1. Henri Gregoire died. — Famous as 

 an ecclesiast and a politician, Gr6goire played a 

 conspicuous part in the great events of the French 

 Revolution, and through him the Convention sanc- 

 tioned the decree of October 10, 1794, for the formation 

 of the Conservatoire des Arts et Metiers and its 

 installation in 1797 in the old priory of Saint-Martin- 

 des-Champs. The Conservatoire is one of the most im- 

 portant scientific and industrial museums in the world. 



May 29, 1864. Georg Bodmer died. — A mechanical 

 inventor who greatly aided the progress of manu- 

 facturers, Bodmer was born in Zurich in 1786. He 

 introduced breech - loading cannon and percussion 

 shells, improved cotton - spinning machinery, and 

 assisted in the construction of the Austrian railway 

 over the Semmering. 



May 31, 1 83 1. Sir Samuel Bentham died. — Born 

 May II, 1757, Bentham was the elder brother of 

 Jeremy Bentham the writer. Apprenticed to the 

 master shipwright at Woolwich Dockyard, he studied 

 naval architecture, and, after serving for some years 

 under the Russian government, in 1795 was engaged 

 by the British Admiralty to introduce machinery into 

 the dockyards. He invented the caisson method of 

 closing docks, designed steam dredgers, and assisted 

 Brunei in his block-making machinery. 



May 31, 1898. Sir Robert Rawlinson died. — Trained 

 by his father, who was a builder in Lancashire, 

 Rawlinson worked on the London and Birmingham 

 railway under Robert Stephenson, became engineer 

 to the Bridgewater Trust, and from 1848 to 1888 held 

 the important post of chief engineering inspector to 

 the Local Government Board. In 1894 he served 

 as president of the Institution of Civil Engineers. 



June I, 1835. Thomas Charles August Dallery died. 

 — One of the pioneers of screw propulsion, Dallery 

 was an organ builder of Amiens. In 1803 he con- 

 structed a steam boat driven by a screw, or " escargot" 

 as he called it, and placed it upon the Seine at Bercy. 

 Imperfections in the machinery, which included a 

 tubular boiler, led to the abandonment of the project. 



June 2, 1891. Sir John Hawkshaw died. — A native 

 of Leeds, where he was born in 181 1, Hawkshaw 

 gained experience on some of the northern railways 

 and then became a consulting engineer in London. 

 He was responsible for the stations and bridges at 

 Cannon Street and Charing Cross, and was engineer to 

 the East London Railway and the Great Severn 

 Tunnel. With Brunlees he was connected with the 

 scheme for a tunnel beneath the Enghsh Channel, and 

 with Barlow he completed the Clifton Suspension 

 Bridge. He was a fellow of the Royal Society and 

 served as president of the Institution of Civil Engineers 

 and of the British Association. 



June 2, 1895. George W. Brown died. — Known in 

 America as " the father of the corn planter," Brown 

 was born in New York State, October 29, 1815. He 

 began Ufe as a farmer, then became a carpenter and 

 assisted in the building of the second railway in New 

 York. He brought out his first com planter in 1851, 

 and by 1866 there were 3000 in use. The invention 

 and development of the com planter was largely 

 responsible for the prosperitv of the middle west of 

 America. 



June 2, 1910. Edward Locher-Freuler died. — A 

 celebrated Swiss engineer, Locher erected factories, 

 water works, railway bridges, and power stations, and 

 in middle life joined the firm of Brandt, Brandan and 

 Co. With his partners he was responsible for the 

 construction under the Alps of the Simplon Tunnel, 

 12 J miles long, which was opened on June i, 1906. 



E. C. S. 

 NO. 2743, VOL. 109] 



Societies and Academies. 



London. 

 Royal Society, May 11. — Sir Charles Sherrington, 

 president, in the chair. — Lord Rayleigh : (i) A 

 photographic spectrum of the aurora of May 13-15, 

 1 92 1, and laboratory studies in connection with it. 

 A photographed spectrum of the aurora on the night 

 of May 14, 1 92 1, shows the negative bands of nitrogen 

 in detail, and the green aurora line which, however, 

 is subordinate. With atomic ray excitation of 

 nitrogen in the laboratory, and better, in the narrow 

 positive column (capillary tube) at low pressure, the 

 development of the negative bands can be imitated, 

 but other nitrogen spectra (line spectrum and second 

 positive band spectrum) persistently appear in 

 addition. The cathode ray spectrum is free from 

 the latter, but the negative bands produced are not 

 developed like those in the aurora, the intensity 

 being much more concentrated in the first band 

 of each group. Hard and soft cathode rays behave 

 alike in this respect. Assuming that helium is the 

 main constituent of the atmosphere above 130 kilom., 

 as the theory of diffusion indicates, then it is difficult, 

 on the hypothesis of positive ray excitation, to explain 

 its absence from the spectrum of this particular 

 aurora, which at Christiania reached to 470 kilom. 

 Experiments on artificial mixtures indicate that it 

 should be visible. With cathode ray excitation, 

 this difficulty would be lessened, but the different 

 development of the nitrogen bands remains. — (2) 

 A study of the presence or absence of nitrogen bands 

 in the auroral spectrum. Spectra of the " Northern 

 Lights " taken in Shetland are compared with 

 spectra of the ordinary night sky at Terling near 

 London. Most of the Shetland spectra show nitrogen 

 bands. None of the ordinary Terling spectra show 

 these bands, though, owing to the long exposure 

 given, the Terling plates show the green aurora 

 line as strongly, or more strongly, than the Shetland 

 spectra. On the occasion of the great magnetic 

 storm and world-wide auroral display of May 13^14, 

 the nitrogen bands were strongly developed at Terling. 

 — C. Chree : The 27-day period (interval) in terrestrial 

 magnetism. There is a tendency in terrestrial 

 magnetism for disturbance to follow disturbance, 

 and calm to follow calm, after an interval which 

 does not depart much from 27 days. The absolute 

 daily range of dechnation at Kew Observatory from 

 1858 to 1900 and the international " character " 

 figures from 1906 to 1920 both show the phenomenon. 

 Generally, it is more clearly exhibited in years when 

 sun spots are few in number or are situated in low 

 solar latitudes. The season of the year seems to 

 have little, if any, influence. — M. Barker : On the use 

 of very small Pitot tubes for measuring wind velocity. 

 The finite pressure in a one-sided Pitot tube for 

 infinitely small openings is comparable with that at 

 the nose of a sphere, of diameter equal to the breadth 

 of the opening, placed in a stream moving with a 

 velocity equal to that at the centre of the pitot 

 opening. This indicates a breakdown in the p — \pv'^ 

 law for Pitot tubes, when the dimensions of the pitot 

 are very small or the velocity very low, p being the 

 density and v the velocity of the fluid and p the 

 pressure difference. The value of rvlv below which 

 the \pu^ law ceases to hold, v being the radius of the 

 circular Pitot tube and v the kinematical viscosity 

 of the fluid, has been determined. For values of 

 wlv<^o, plpv^ is greater than \ ; below this value 

 there is a viscosity effect in the form of an additional 

 pressure comparable, as before, with that at the 

 nose of a certain sphere. — E. T. Paris : On doubly 

 resonated hot-wire microphones. The properties of 



