April 30, 1903 



NA TURE 



619 



lines, their designations, assumed wave-lengths, and relative 

 intensities being as follows : — 



H(, 38S9, (1) ; H<f, 3970, (3) ; H5, 4102, (8) ; H 7 , 4341, (10) ; 

 — , 4643, (II) ; and U$, 4S62, (9). 



No dark lines are shown on the photograph, but this 

 may possibly be due to the small dispersion employed. The 

 same lines, together with the nebula line at A 5003, are 

 shown on spectrograms obtained on March 29 and 31, and 

 April 1, the nebula line appearing as brighter than Hf 

 and of intensity 2-3. Later photographs contain lines at 

 the estimated positions A 4176, A 4240 and A 4462. 



Prof. Pickering remarks on the utility of such a series 

 of systematic observations as are carried on under the 

 Draper memorial fund, and states that even in the absence 

 of Prof. Turner's discovery and prompt announcement. Nova 

 Geminorum would have been discovered, for its spectrum 

 was .1 very conspicuous object on the Harvard photograph 

 of March 25 (H.C.O. Circular, No. 70). 



Recently Discovered Terrestrial Gases in hie 

 Chromosphere. — Owing to their proved relationship to 

 helium, Prof. S. A. Mitchell, of Columbia University, sus- 

 pected that the recently discovered gases neon, argon, 

 krypton, and xenon might be found to exist in the chromo- 

 sphere, and in order to test his supposition he compared the 

 wave-lengths of the lines in their respective spectra with 

 the wave-lengths of the chromospheric spectrum obtained 

 by himself during the Sumatra eclipse. 



Owing to the low densities of the new gases, it is to be 

 expected that, as is the case with helium, thev will not 

 appear in the normal solar spectrum, even though they 

 may appear in the spectrum of the chromosphere ; and 

 again, owing to the low atomic weights of neon and argon, 

 Prof. Mitchell expected that these two gases might appear 

 in the spectrum, whilst krypton and xenon, the atomic 

 weights of which are greater, would probably not so 

 appear. 



As a result of his comparison Prof. Mitchell comes to the 

 conclusion that lines due to neon and argon are present in 

 the chromospheric spectrum, but the evidence as to the 

 presence of krypton and xenon is, at present, inconclusive. 

 Lines which are due to the more volatile gases of the 

 earth's atmosphere (i.e those which are uncondensed at 

 the temperature of liquid hydrogen), as published by Liveing 

 and Dewar, appear at AA 4047, 439S, 4422, 4431, 4540 and 

 4S44, and the strongest argon lines, viz. those at AA 4180.3, 

 4200S, 42595, 42668 and 44303, are also represented in 

 the spectrum of the chromosphere. 



Prof. Mitchell suggests that these gases may have come 

 to the earth's atmosphere from the sun, as suggested in 

 the theory put forward by Arrhenius, which supposes that 

 ionised particles are constantly being repulsed by the 

 pressure of light, and thus journey from one sun to another 

 (Astrophysical Journal, No. 3, vol. xvii.). 



Catalogue of Measures of New Double Stars. — In 

 Bulletin No. 29 of the Lick Observatory, Prof. R. G. Aitken 

 publishes a further addition of 117 new double stars and 

 their measures to his new catalogue of these objects; the 

 earlier sections of this catalogue have alreadv appeared in 

 previous numbers of the Lick Bulletins and in the Astrono- 

 mische Nachrichten. 



The present section deals with Nos. 313 to 429 (Aitken) 

 inclusive, and gives the position for 1900, the number in 

 previous catalogues, the magnitude and the dates and 

 figures of the various measures for each star. More than 

 one-half of the pairs in this section are separated by angular 

 distances not exceeding 1", and more than three-fourths are 

 only separated by 2" or less. 



The doubles have been discovered with the 12-inch 

 telescope, but nearly all the measures have been made with 

 the 36-inch. 



" The Cambrian Natural Observer." — The latest issue 

 of this interesting little volume, which is the official organ 

 of the Astronomical Society of Wales, contains many 

 interesting records of observations, both astronomical and 

 meteorological, made by members of the Society during 

 1902. In future the " Observer " will only appear annually 

 instead of quarterly as hitherto- 



NO. 1748, VOL. 67] 



SEISMOLOGICAL NOTES. 



"THE last publication of the Earthquake Investigation 

 Committee of Japan contains five papers illustrated 

 by twenty-six plates, all of which are the work of Dr. F. 

 Omori. The first of these refers to a horizontal pendulum 

 tromometer, which is essentially a conical pendulum seismo- 

 graph carrying a load of 50 kg. and writing indices with 

 a multiplication of 120. In addition to recording earth- 

 quakes, it indicates the almost continual existence of 

 " micro tremors," the periods of which are about 03 second 

 and the range 0013 mm. When "pulsatory oscillations," 

 which are a larger form of disturbance than the tremors, 

 are in evidence, it would appear from the illustrations which 

 are given of these movements that they might seriously 

 interfere with the character of an earthquake record. 



In a communication on the overturning and sliding of 

 columns, the relationship between the horizontal component 

 of earthquake motion and the displacement of bodies which 

 are not attached to the ground, but simplv rest upon the 

 same, is discussed and illustrated with considerable detail. 

 The effects of vertical motion are referred to, and cases are 

 pointed out where gate-posts and buildings have been caused 

 to jump. A paper bearing upon the seismic stability of tall 

 chimneys gives the results of experiments upon the vibration 

 of such structures. The remaining papers respectively refer 

 to the vibration of the piers of railway bridges as caused by 

 traffic, and the vibration of walls at the time of earthquakes. 



These excellent publications are undoubtedly of great 

 value, especially 10 those who have to construct to resist 

 earthquake movements ; but if the author could have given 

 more complete references to investigations made by himsi ll 

 and also by others in connection with similar inquiries, their 

 value would have been enhanced. 



Other seismological notes are found in the reports of the 

 Physico-Mathematical Society of Tokyo. In one of these, 

 No. 16, Dr. Omori gives a summary of analyses he has 

 made of seismograms of distant earthquakes. This is 

 followed by notes relating to the transit velocity of the first 

 preliminary tremor of earthquakes of near origin. We are 

 told that the duration of these early movements has a 

 constant relationship to the distance they have travelled. 

 Therefore, if this distance is known, and the time of arrival 

 of the large waves has been noted, it is an easy matter to 

 determine the time at which the preliminary tremors must 

 have arrived. With this factor and with a knowledge of 

 the time at which they originated, their velocity may be 

 calculated. A mean for this is given at 5 or 6 km. per 

 second, whilst a mean value determined from observations 

 is 8 km. per second. In arriving at these results, it must 

 not be overlooked that in certain cases, at least, there has 

 been an unavoidable want of precision in locating origins ; 

 the time of occurrence at an origin has been taken as the 

 mean of times observed at stations regarded as being near 

 to the same, and it has been assumed that the waves followed 

 spherical paths. These and other factors have no doubt 

 contributed to the wide limits assigned to the results of 

 these investigations. 



In the tenth number of the new series of publications 

 issued by the Earthquake Commission of the Vienna 

 Academy of Sciences, Dr. E. v. Mojsisovics gives a chrono- 

 logical series of notes relating to 157 earthquakes which 

 in 1901 were recorded in various parts of the Austrian 

 Empire. The first of these catalogues, which consists of 

 observations made for the most part without the aid of 

 instrumental appliances, was issued in 1898. 



In addition to these lists of local disturbances, which may 

 be compared to the slight shocks which from time to time 

 are felt in this country, the Academy also publishes registers 

 of disturbances which have originated at great distances 

 and shaken the world throughout its mass. Illustrations 

 of these latter are found in the eleventh and twelfth numbers 

 of the publications, the former referring to Trieste and the 

 latter to Kremsmiinster. 



At the first of these stations, three Rebeur-Ehlert pendu- 

 lums have been kept at periods of about eight seconds, whilst 

 at the second, similar instruments have periods of from three 

 to four seconds. In 1901, at Trieste, 187 earthquakes were 

 recorded, whilst at Kremsmiinster only eighty-one were 

 noted. Although the natural period of the pendulums has 



