APRIL 15, 1897 | 
NATURE 
309 
The greatest disturbance appeared at the third pendulum 
(S.W. to N.E.), with oscillations 6 cm. large; the maximum, 
with two well-defined periods, was from 8h. 23m. 52s. until 
gh. Sm. 43s. a.m. Tremors followed until 11h. 3om. a.m. ; 
the preliminary tremors of this 
7h. 45m. 25s. a.m., showed three well-marked maxima. Other 
very small tremors preceded, the pendulum being troubled all 
the preceding night, perhaps by the winds. 
On February 11, there was a small disturbance on the second 
and third pendulum 1th. 39m. 48s. ; February 13, a very great 
one on all three pendulums from 2h. 31m. 54s. until 3h. 8m. 
a.m., with oscillations up to as much as 2°1 cm., and preceded on 
pendulum three by a preliminary motion, on February 12, from 
1th. 2m. 2s. p.m. until 1th. 34m. 38s. p.m. 
A very great perturbation was observed on February 19, on 
the third pendulum, from 1oh. 11m. until roh. 39m. p.m. ; and 
on February 20, from oh, rim. 15s. until rh. 20m. 10s. a.m. 
The first pendulum (E. to W.) had a very great motion from 
oh. 11m. 16s. until th. 49m. a.m., February 20, followed by 
a long series of tremors. The second pendulum was not in 
activity. 
Dr. Ehlert (Strassburg) has put the box with the three pen- 
dulums on a short, stout, isolated sandstone pillar, to avoid 
the earth-waves being concealed or wholly annihilated by 
the frictions and elastic motions taking place in a large 
pillar of masonry; and the pendulums, set up in such 
a manner, give very accurate records of vibrations, change 
of level, &c. They can be made extremely sensitive. The 
whole instrument may be purchased for 517, with re- 
cording apparatus and lamp (Strassburg, I. and A. Bosch) ; 
and I should like to recommend it, for the seismic survey of 
the world, for each station of this international survey. The 
distinct directions and movements of the three pendulums are 
showing (1) each motion of the earth-crust coming from what- 
ever an azimuth ; (2) the chief direction of the seismic wave ; 
(3) the temporary figure-of the wave ; (4) their splitting-up in 
different trains of waves. They are disturbed also by vertical 
shocks. G, GERLAND. 
Strassburg, March 31. 
Relationship between the Masses and Distances of the 
Four Outer Planets. 
Ler the mean distance of Jupiter be the unit of measurement 
for the four outer planets. The distances are then as follows. 
Jupiter. Saturn. Uranus. Neptune. 
I 1°8338 36869 5°7765 
Now take the following numbers as the masses— 
Jupiter. Saturn. Uranus. Neptune. 
312 92°513 13604 15°969 
and multiply the masses into the distances. We then obtain 
Jupiter. Saturn. Uranus. Neptune. 
312 169°65 507157 92°245 
J Ss U N 
Let the last series of numbers be J, S, U, N, respectively. 
Then 
Wes = N?. 0) 
1) ff SNES dg: Sea 3 (2) 
UNS = J... s SG 
In fact, the numbers are in geometrical progression, having a 
common ratio R = 1°8391. So that 
U i, = io eeeceeers (5)! 
UR=S. : . (5) 
(Uy IPs . (6) 
The common ratio 1°8391 is nearly the mean distance of 
Saturn 18338, and is one of the solutions of a biquadratic 
equation 
xt — 2x3 + 1=0. 
G. E. SUTCLIFFE. 
The Ifermitage, Coorla, Bombay, March 19. 
X-Ray Photography. 
Ir may interest the readers of NATURE, that it is possible to 
take shadowgraphs (so-called) instantaneously without any 
special arrangement of induction coil or deviation in the form of 
Jackson tube. 
NO. 1433, VOL. 55] 
pendulum, commencing | 
The apparatus used consists of 10-inch Apps’ induction coil, 
a Jackson focus tube supplied by Messrs. Newton (one of a set 
| of twenty-five I have in my possession), and a set of small 
secondary batteries, about 30 ampére hour capacity, six cells in 
the set. The induction coil is of the ordinary type with ordinary 
commutator, 
For the purpose of obtaining these results in such short 
| exposures, a special choice of tube is necessary, working the 
tube for a considerable period before desired condition is arrived 
at, and that condition judged by experience, for no ampere 
measurement will give the information. The tube must be 
strongly heated by a spirit lamp, and when the desired con- 
| dition (tube being of course connected with coil) is arrived at, 
| the exposure must take place. 
(1) By instantaneously turning current,on and off. 
(2) By interposing a 4-inch iron plate between tube and object 
to be shadowed, removing plate for the exposure. 
Having carefully timed the exposures, I have been able to 
repeat the experiment with assured success. For some time 
past I knew that hands and arms of children could be taken in 
from twenty to thirty seconds, but have now succeeded in taking 
children’s hands in half a second (showing all bones and cell 
tissue of bones), and adults’ hands, bones of wrist, and even 
arms, with exposure of only one second, again showing cell 
tissue of bones. 
It is interesting to note that everything connected with the 
production of these results was made in England. 
WILLIAM WEBSTER. 
Art Club, Blackheath, March 30. 
A New Scientific Club. 
My attention has been drawn to a circular in favour of a 
new Club, in which my name appears as one having consented 
to become a member. I know nothing of the Club, nor have 
I in any way authorised the use of my name. 
12 Arundel Gardens, W., April 9. 
W. RAMSAY. 
DEEP-SEA FISHES OF THE NORTHERN 
ATLANTIC. 
HE examination of the deep-sea fishes which have been 
collected by means of the dredge or trawl during 
the last twenty-five years, has now been almost com- 
pleted ; at least the results of this examination, as far as 
it has gone, are now before us, and form the most inter- 
esting and attractive portion of the ichthyological litera- 
ture of our time. The harvest reaped by the various 
expeditions, surveys, and private enterprises, which have 
been fitted out to explore the mysteries of the sea, has 
far exceeded the most sanguine expectations, and it is 
satisfactory to find that the six or seven volumes devoted 
to ichthyology have been placed before the public in a 
style and with a wealth of illustration worthy of the 
interest attached to the subject. The first to appear was 
the volume descriptive of the deep-sea fishes collected 
during the Norwegian Expedition to the North Atlantic 
from 1876 to 1878, by R. Collett (Christiania, 1880, 4to, 
pp- 166, with five double plates) ; this was followed, in 
1887 by the Report on the Deep-sea Fishes collected 
during the Challenger Expedition (1873-76), in which were 
incorporated the proceeds of the Faer6e Channel Explora- 
tion (1880 and 1882) (London, 1887, 4to, pp. Ixv. + 335, 
with 73 plates) ; the collections made by the French ex- 
peditions of the Zravail/eur and Talisman (1880-83) 
were described by L. Vaillant (Paris, 1888, 4to, pp. 406, 
with 28 plates); in the Indian Ocean, H.M. Indian 
Marine Survey steamer /zvestigator has added largely 
to our knowledge of the bathybial fauna from year to 
year since 1885, the collections being described by A. 
‘Alcock in a series of papers which appeared in periodicals, 
and were supplemented afterwards by “ Illustrations,” of 
which three parts, with fifteen plates in quarto, have been 
issued under the authority of the Director of the Royal 
Indian Marine in Calcutta, 1892-95 ; finally, the collec- 
tions made in the North Pacific by the U.S. Fish 
