Fuly 16, 1885] 
NATURE ® 
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John with those of the same formation in Europe.—On the Wall- 
bridge Hematite Mine, as illustrating the mode of occurrence of 
certain ore deposits, by Prof. Chapman. The particular mine 
referred to has been practically worked out, and in the process 
a clear idea of its character has been gained. It is found to be 
a ‘‘*stockwork,” or irregular mass, and not, as had been sup- 
posed, a vein. Prof. Chapman regards it as typical of a large 
class of deposits in the vicinity.—On Cambrian rocks of the 
Rocky Mountains, by Dr. G. M. Dawson. These rocks are the 
oldest of those shown in the mountains between the 49th paral- 
lel and the Bow River. They are of great thickness, and include 
at one horizon red beds with pseudomorphic salt crystals, sun- 
cracks, &c. Fossils have so far been obtained from four locali- 
ties only, and these appear to indicate the horizon of the 
Prospect Mountain group as olevellus shales of Eureka, Nevada. 
—On the geology of South-Eastern Quebec, by Thos. Macfar- 
lane.—On the geology of Thunder Cape, Lake Superior, by 
Thos. Macfarlane. The last two papers were read merely by 
title, Mr. Macfarlane adding a few explanatory remarks.—Notes 
on the geology and fossils of Prince Edward Island, by Francis 
Bain, communicated, with remarks on the fossils, by Geo. 
Wm. Dawson. The paper contained the results of explorations 
by Mr. Bain, with mention of fossil plants found by him in 
different parts of Prince Edward Island. It appeared from 
these observations and fossils that the red and grey sandstones 
and shales of which the island is composed are divisible by 
superposition and fossils into three groups : (1) the Permo carboni- 
ferous as originally established by Sir Wm. Dawson, with local 
additions made by subsequent observers; (2) a formation re- 
garded by Mr. Bain as probably Permian, and corresponding 
to the Lower Triassic of Dawson and Warrington’s report ; (3) an 
overlying series, probably Triassic, and corresponding to the 
Upper Trias of the above report. Sir Wm. Dawson discussed 
the evidence of the fossil plants as bearing upon the above views. 
In Sections I. and II. the following (among others of a more 
or less literary character) were read :—(r1) Population francaise du 
Canada de 1608 4 1631; (2) A travers des registres du XVII. 
siécle, by the Abbé Tanguay.— The manifestation of the zesthetic 
faculty among primitive races, by Dr. Daniel Wilson. This 
paper discusses the evidence of the zesthetic faculty, and the 
practice of imitative art among ancient and modern uncivilised 
races. The archeological investigations in European prehistoric 
remains showed a nearly universal absence of imitative art 
throughout the whole Neolithic period and the subsequent age 
of bronze. But behind this lay the vastly more remote age of 
the Cave-men of Southern France, with their singular indica- 
tions of remarkable artistic skill. This the author compared 
with such evidences of imitative art as are familiar to us in the 
work of many native American aborigines, and stated his 
reasons for tracing all alike to efforts at sign-language and 
ideographic expression of facts and thought. This was illus- 
trated from an analysis of native Indian languages in their 
terms for giving expression to the language of art.—Palzo- 
lithic dexterity, by Dr. Daniel Wilson. In this paper Dr. 
Wilson drew attention to the ingenious profile drawings now 
familiar to us as the products of the ancient Cave-men of 
Southern France, and showed that by the direction of the pro- 
files they were divisible into right and left-hand drawings. In 
so far as the examples can yet be adduced, the right-hand draw- 
ings are to those of the left hand as about two toone. The per- 
centage of left-hand drawings is thus greatly in excess of what 
would now be found. But it probably shows at that extremely 
remote period the bias of prevalent usage which, however 
originating, has sufficed to determine the nearly universal pre- 
dominance of the preference for the right hand within the whole 
historical period. 
ON THE OBSERVATION OF EARTH-TIPS 
AND EARTH-TREMORS 
JN a paper read before the Seismological Society of Japan on 
February 15, 1883, I collected together a number of facts 
which lead to the belief that districts in all quarters of the globe 
have from time to time been subject to slow changes in level. 
Amongst these evidences may be mentioned the changes 
which have been recorded by many observers in the position of 
the bobs of pendulums. That pendulums had not always hung 
in the same vertical line was sometimes indicated by the position 
of a multiplying index, and sometimes by the position of the 
stile of a pendulum as seen through a microscope. Another 
class of observations have been made by recording the position 
of a spot of light reflected from a small mirror, the mirror being 
so suspended that it was caused to turn by the slightest displace- 
ment of the pendulum relatively to the earth. A third class of 
records have been made with horizontal pendulums, the multi- 
plying indexes of which have been observed to move from side 
to side as if the foundation on which the pendulums rested was 
being slowly tilted. 
A fourth order of observations have been those which have 
been made with delicate levels, the bubbles of which slowly 
move along the containing-tubes in a manuer difficult to explain. 
A fifth class of records indicating changes in level are those 
which have been made by observing the displacement of an 
image reflected from the surface of mercury. 
A sixth kind of records are the changes sometimes observed 
in the levels of lakes and ponds. At the time of great earth- 
quakes, at places remote from its origin, where there was no 
perceptible motion of the ground, the water of lakes and ponds 
have been observed to slowly rise and fall as if the basin in 
which they rested was being slowly tilted. 
To the above six classes of records a number of miscellaneous 
observations might be added, all of which find an easy explana- 
tion if we admit that from time to time there are slow tips in the 
soil. 
Another phenomenon which has been observed is ‘that the 
surface of the ground is from time to time in a state of tremulous 
motion. These movements have been noted by observing the 
stile of a pendulum with a microscope, the end of a light mul- 
tiplying index attached to a pendulum, the quivering and erratic 
motion of a spot of light reflected from a mirror connected with 
a pendulum or reflected from the surface of mercury. __ 
An historical account of the various observations which have 
been made upon earth-tips and earth-tremors may be found in 
the reports of George and Horace Darwin to the British Asso- 
ciation in 1881 and 1882. 
Detailed accounts of the observations made in Italy are con- 
tained in Rossi’s ‘‘ Meteorologica Endogena.” ; 
An account of a considerable portion of the work which has 
been accomplished in Japan may be found in the Zransactions 
of the Seismological Society, in the reports which from time 
to time I have had the honour of forwarding to the British 
Association, and in the pages of NATURE. ; 
As it seems that these phenomena are gradually attracting an 
increasing attention, it is my intention in the following notes to 
give a brief account, not so much of the results I have ob- 
tained by observing earth-tremors and pulsations, but of the 
methods by which these results have been obtained, trusting 
that my experiences may be of value to those who are desirous of 
experimenting in this direction. ; ‘ 
Among the first instruments I employed were microphones in 
conjunction with telephones and delicately-suspended short- 
period light pendulums. From time to time the telephones 
emitted strange sounds. As to what was the cause of these 
noises I am unable to say. Unless you kept your ear continu- 
ally at the telephone there did not appear to be any method of 
obtaining a satisfactory record, so that, after much labour, these 
instruments were eventually discarded. For very similar reasons 
the small pendulums which were often in a state of tremor were 
also discarded. Ane 
The next class of instrument which I employed was similar to 
an apparatus suggested by Sir William Thomson and used by 
George and Horace Darwin in the Cavendish Laboratory when 
experimenting on the lunar disturbance of gravity. Any one 
who has read Mr. Darwin’s account of these experiments will 
recognise the unusually great care which is required by any one 
who undertakes to make observations with such instruments. 
As I was without either assistants or a laboratory, and as my 
instruments were of the roughest description, my attempts at 
making satisfactory observations altogether failed. I certainly 
saw that the spots of light were continually shifting in position, 
but whether this was due to a tip of the soil or simply to con- 
tractions and expansions in portions of my instrument, I was 
unable to determine. 
After much trouble and considerable expense, I very reluct- 
antly gave up the pendulums and mirrors, and sought for 
apparatus of a still simpler kind. Having accidentally read an 
account of Plantamour’s observations with levels, the simplicity 
of the apparatus induced me to borrow a pair of astronomical 
levels from the Imperial Observatory and follow his example. 
