ily) REPORTS ON THE STATE OF SCIENCE, ETC. ‘ 
Disturbance at Colombo, Ceylon. 
The following note was forwarded by Mr. Bamford on 1921, June 22 :— 
“The shock of December 16, 1920, gave the seismograph zero a permanent 
shift of 84 mm., or about 5”, the West end of the pillar being raised. <A print 
of the corresponding records is enclosed. Two West to East levels, one on the 
seismo-pillar, 15 feet deep, the other on the pillar of the new transit instrument, 
2-3 feet deep, were available for examination. Their curves are shown (Curves I. 
and II.). The plotted points are the means of three readings, approximately 
at 8 A.M., noon, and 4 p.m. (1.8.T.), except on the 12th and 19th (8 a.m. readings 
only), and on the 18th (8 A.M. and noon readings only, for the transit level). 
The curves run fairly parallel, except on the 16-17. We may therefore take 
the effect of the earthquake on the seismo-pillar to be a shift of rather over 1’. 
‘The North to South level on the seismo-pillar (Curve III.) shows no effect at 
all, unless it is masked by a simultaneous shift due to meteorological changes, 
such as frequently occurs. In this connection it may be mentioned that the 
daily period of the seismo-pillar (the East to West component of which used 
to be 5’, the North to South component much smaller) was considerably reduced 
last year by the addition of verandahs to the North and South of the seismo- 
graph room, and by the addition of a new transit room to the East, so that 
ea seismograph room is no longer at the extreme East of the Observatory 
building.’ 
The three curves forwarded by Mr. Bamford certainly all show a sympathetic 
drop on December 17, and a sympathetic rise from about December 18.5 to 20.0. 
Outside these limits their trends are unsympathetic and even opposed. It is 
possible that the movements between December 17+20 are due to the earthquake, 
but large changes of a seismograph trace may be due to creep of the boom 
needle point in its cup, which in the Colombo (Milne) instrument is 
hemispherical. 
Disturbance at Oxford. 
On the other hand, we are fortunate to have a remarkable observation at 
the Radcliffe Observatory, Oxford, kindly communicated by Dr. Rambaut. It 
appears that Mr. W. H. Robinson happened to be chbserving the level-error 
of the Transit Circle at the time of the earthquake, and after making a setting 
‘was astonished to see the reflected image of the wires slowly move away 
until it reached a distance of about 4”; it then as slowly returned to the direst 
wire, repeating this many times during the half-hour’s watching from 12h. 55m. 
to 13h. 25m. At times the amplitude of the oscillation was rather greater 
than 4”, possibly 5”. There was a complete absence of tremor or quick vibration 
and diffusion such as those ordinarily observed, caused at certain times by 
the engine of the University Press, and occasionally by passing heavy traffic.’ 
The extreme readings of the R.A. micrometer were 21.277 and 21.333; on 
December 17 and 18 the mean readings were 21.356 and 21.353, agreeing nearly 
with one extreme, and certainly not lying between them. The suggestion is 
that ‘the oscillation took place in such a way as to lift the Eastern pivot rela- 
tively to the Western by about 0.0006 in. (pivots 50 in. apart).’ The observa- 
tions were communicated by Dr. Rambaut to the ‘Monthly Notices’ of the 
Royal Astronomical Society in 1921, April, but the facts were set down on 1920, 
December 30. 
Telegraphic Transmission of Earthquake News. 
It is not often that rapid communication of seismological observations is 
seriously needed. For most earthquakes leisurely transmission by post is quite 
sufficient, for the accurate determination of an epicentre is best undertaken 
when all the information has been collected. As regards preliminary determina- 
tions, they can often be made from a single completely equipped station or 
from one or two stations near together, in friendly communication by postcard. 
The quake of December 16, however, drew attention to the desirability of 
having in reserve some means of telegraphic communication. Inquiry was 
“r. 
