l82 



NATURE 



[April 7, 192 1 



caustic alkali. The most promising method, how- 

 ever, is the direct oxidation of a hydrocarbon mixture 

 such as petroleum or paraffin wax by atmospheric 

 oxygen in presence of a catalyst consisting of a 

 resinate of vanadium, manganese, etc. In this 

 process, due to Franck, a net yield of 70-75 per cent, 

 of fatty acids suitable for soap-making, esterification 

 to produce fats, and other purposes is claimed. The 

 process was in operation on a technical scale. 



Messrs. A. Gallenkamp and Co., 19-21 Sun Street, 

 E.C.2, have issued a revised catalogue of electric fur- 

 naces suitable for a variety of laboratory purposes. 

 The advantages possessed by electric furnaces are evi- 

 dently receiving due recognition, for Messrs. Gallen- 

 kamp state that they have sold more than iioo fur- 

 naces during the past five years. The construction of 

 these furnaces is very simple ; a tube or muffle of 

 fused silica is wound with a resister wire and the 

 exterior well lagged to diminish heat loss. Such 

 furnaces are capable of temperatures up to 1000° C. ; 



beyond this point it becomes necessary to employ 

 platinum-foil windings and refractory tubes or muffles. 



Messrs. Bernard Quaritch, Ltd. (ii Grafton 

 Street, W. 1), have just issued a catalogue (No. 362) 

 of second-hand books and periodicals ranging over a 

 variety of subjects. The sections most likely to interest 

 readers of Nature are those devoted to botany, early 

 science, natural and physical sciences, and periodicals. 

 In the latter there are many sets and long runs, some 

 not otherwise easily procurable. Among the items 

 are Annales de Chimie %t de Physique (1789-1909), 

 the Journal of Botany (vols, i.-xlvi.), Philosophical 

 Transactions of the Royal Society (1665-19 18), and 

 Transactions of the Zoological Society of London 

 (1833-19 1 5). There is also a set of the publications of 

 the Ray Society (1844-19 15). 



Erratum. — Mr. W. J. Perry writes : — " In the 

 article in Nature of March 31 entitled 'The Develop- 

 ment and Spread of Civilisation,' I inadvertently put 

 3700 B.C. for a date that should be 3400 B.C." 



Our Astronomical Column. 



Recent Brilliant Fireballs. — Mr. W. F. Denning 

 writes that he has received twenty-five accounts 

 of the brilliant fireball of March 16; and has been able 

 to revise his preliminary deductions, which were based 

 on scanty data. The height of the object was from 

 about 68 to 25 miles from over Moffat to Berwick, 

 path 81 miles and velocity 11 miles per second, 

 radiant point at 72°+ 12°. The average of a number 

 of estimates of the duration of flight was 73 seconds. 

 The radiant point does not correspond with any 

 known shower in March, and the position shows that 

 the fireball was overtaking the earth in its orbit and 

 moving with very slow apparent velocity. It is curious 

 that so many fireballs appear to be revolving in direct 

 orbits, but the fact seems clearly proved on ample 

 evidence. It is also a significant feature that many 

 fireballs of the slow-moving type exhibit radiants 

 which are situated on or near the ecliptic. 



Splendid fireballs were also observed on March 

 25 i3h. 13m. and March 29 7h. 27m. G.M.T. from 

 the metropolitan district and south-eastern counties. 

 A number of descriptions have been received, but few 

 of them are exact and accurate. The approximate 

 real paths derived from the best data available at the 

 time of writing are : 



Height Height Velocity. 



G.M.T. at first, at end. Path. Miles per Radiant. 



h. m. Miles. Miles. Miles, second. ° ° 



March 25 13 13 67 56 88 — 181 — 29 

 29 727 61 47 71 12 \ g^-io 



The former appears to have a possible connection with 

 the comet of 1264, for which Prof. A. S. Herschel 

 computed a radiant at 182-5° — 28° on March 25. This 

 comet was a brilliant one, and passed within two 

 millions of miles of the earth's orbit. 



The past month of March has furnished large fire- 

 balls of unusual numbers and interest, and the popular 

 idea has been to ascribe them to the oncoming comet 

 of Pons-Winnecke, though, as a matter of fact, no 

 connection whatever can be proved. 



Another Investig.ation of the Einstein Spectral 

 Shift. — The Comptes rendus of the Paris Academy of 

 Sciences for March 7 contains an investigation by 

 M. A. Perot, communicated by Dr. H. Deslandres. 

 The investigation is based on a study of the mag- 



NO. 2684, VOL. 107] 



nesium spectrum. The wave-lengths in Angstrom 

 units of the lines b,, b^, b^ in the arc at atmospheric 

 pressure were found to be 5183-614, 5172-690, and 

 5167-340 respectively. 



Tests were then made at different pressures, and 

 it was found that the value of dA/A per atmosphere 

 is 1-35/ 10' for bi and 1-67/10* for fe„ so that com- 

 parison between b, and b, should give the pressure 

 of the region where the spectral lines are produced. 

 In this manner, by a discussion of solar and arc 

 spectra obtained by photography in the year 1911, the 

 value of the pressure of the absorbing layer on the 

 sun is found to be equivalent to —6 cm. of mer- 

 cury ± 20 cm. Of course, the pressure cannot actually 

 be negative, but it is inferred that it is very low, and, 

 consequently, that nearly the whole of the atmospheric 

 term 1-35/10° must be applied to the solar measures 

 of bj to make them comparable with the terrestrial 

 ones. The value of dA/A for sun minus arc is then 

 (i-i6+i-35)/io% in good agreement with the Einstein 

 value, which is 2- 12/ 10*. The author has failed to 

 notify the regions of the sun to which the measures 

 apply. This should have been done, in view of the 

 considerable differences for different regions found 

 by Mr. Evershed and others. 



Nova Aquil.^ III. — In the Journal of the Man- 

 chester Astronomical Society for the sessions 1917-20, 

 which has recently been received, there appears a 

 valuable series of photographs of the spectra of Nova 

 Aquilae III. taken by Mr. C. F. Butterworth with a 

 6-3-in. prismatic reflector. The period covered is from 

 June 10 to November 14, 1918, and thirty-six photo- 

 graphs are shown taken on twenty- two days distributed 

 fairly evenly over this period. Although the disper- 

 sion obtained was extremely small (243 A.U. to 

 I mm.), the photographs are evidently good enough 

 to stand considerable enlargement and show plenty of 

 detail. The general sequence of changes in the spec- 

 trum is well shown, and many of the smaller details — 

 such as the complex structure of the hydrogen bands — 

 may also be detected. The series as a whole forms 

 a useful addition to the observations already published 

 concerning this important nova. In addition, Mr. 

 Butterworth gives a table of measures of the breadths 

 of the more important bright bands at four different 

 stages of the star's career. 



