174 PROCEEDINGS OF SECTION A. 
Tt is called the gravimeter, and is intended to determine the 
absolute value of the force of gravity. 
It seems to have reached, or nearly reached, the state of per- 
fection, and it is quite probable that it may put a very different 
aspect on the future of gravity work. 
Seismology is one more subject of terrestrial physics, which, as 
it will necessitate more systematic and thorough investigation in 
Australia in the immediate future, it is in accordance with the 
pian of this address that I should mention it. 
I know that there is already a committee for seismological 
research, which was created by our Association, and that its 
activity has been shown by its interesting reports presented at 
our past meetings, and published in our volumes. 
I may, however, be allowed to point out some new matters, with 
the hope that my remarks on the subject may not be construed 
as interfering with the functions of this worthy committee. 
The seismological committee of the British Association for the 
advancement of science some time ago addressed a circular to the 
Australian Observatories, and, I suppose, to other Australasian 
Institutions, in which we were requested to co-operate with other 
parts of the world by securing instrumental records of the correct 
times and phases of “earthquakes and tremors, stating also that 
these records should be obtained with the same class of in- 
struments. 
The proposed instruments are intended to give a photographic 
record of one horizontal component. 
Hitherto in the Australian colonies there has been no attempt 
made to carry on this class of observations in accordance with 
any concerted method, and with sufiicient accuracy and complete- 
ness to efficiently serve the purposes of modern research. It is to 
be regretted that in recent investigations of earthquake periodicity, 
and in the relation of earthquake frequency with barometric 
conditions, the Australian contribution of data has been regarded 
as somewhat uncertain or deficient. 
These questions, in addition to that of the velocity of propaga- 
tion, and many others more especially of a geological character, 
are of the greatest interest, and I have no doubt that our 
seismological committee will make suggestions in order that the 
requests of the Home investigators may be complied with. The 
seismological instruments we possess at present in the Australian 
colonies are not, I am afraid, sufficiently sensitive. In Melbourne, 
for instance, the seismograph of the Observatory is not so sensitive 
as the unifilar and bifilar magnetographs. 
Consequently the slight earth tremors, which are probably of 
more frequent occurrence than we may suspect, evade observation ; 
and these are of no less importance from the scientific point of 
view than violent shocks. 
