"i 
: 
_I see the less I like it. 
Aug. 21, 1873] 
three or four feet of wing—who will swoop and take meat from 
a basket on a man’s head, any day, or even from his hand. A 
score or two of these circling about the kitchen and outhouses, 
may be watched with advantage from the house-top, as is evi- 
dent. The difficulty is to reproduce, in description, anything 
definite, from the copiousness of the evidence. I can therefore 
only express distinctly the conclusions I formed :—(1) that it was 
utterly incomprehensible ; (2) that there mst be some unper- 
ceived source of motion ; (3) that it mzght be (and probably 
was), a subtle utilisation of the varying air currents met with or 
sought for. This conclusion lands one in a new set of perplex- 
ities, it is true ; but it is the least opposed to reason, however ill 
it may accord with some of the facts as interpreted by us. 
Vultures are large heavy brutes, with comparatively little 
wing-power, and their flight is far slower and heavier. They very 
commonly rest on the ground, doing nothing, and if disturbed, 
the effort to rise is evidently a toilsome one. Nevertheless, they 
too possess, and largely exercise the power, of sustaining them- 
selves in mid-air without apparent action, Not that they ever 
rest motionless, but they sweep about in endless paths with 
hardly ever a beat of the wing except on occasion, in this respect 
seeming to husband their strength much more than the kites, 
who are always on the move, and wheel in much sharper curves. 
Iwas a good deal impressed, at one time, with the notion that 
the secret lay in slants of wind taken advantage of, but the more 
It is impossible to conceive upward 
currents as commonly strong enough to support a dead bird simi- 
larly extended. And though I am not prepared to assert that I 
have ever seen birds floating motionless where there was 7o wind, 
yet if we are to take the vertically resolved portion of wind, 
considered as essential, as the supporting agency, what becomes 
of the horizontal force? Given a sufficient momentum, one 
could conceive an economic expenditure of it, but not enough to 
explain the endless wheelings of vultures, much less the long 
continued poising without forward or backward movement of 
eagles. 
in fine, I can only echo Mr. Guthrie’s appeal for further ex- 
planation ; but I beg that we may have no nonsense about 
“bones filled with air.” One is tempted to ask in that case if 
death solidifies the bones, to account for the undeniable weight 
and density of a goose. J. HERSCHEL 
Bangalore, July 6 
Earthquakes in the Samoan Islands, South Pacific 
ON two former occasions I have contributed to NATURE notices 
of the earthquakes experienced in these islands. I will now 
continue my list from the commencement of 1872, 
On Marck 22, at 1.25 P.M., there was ‘a shock from N.E., 
motion horizontal, Vibration continued 15 seconds. For 
several seconds before the motion was fclt, and during the whole 
time of vibration, there was a noise like distant thunder. 
On April 8, at 3.10 P.M., there was .a slight shock, hori- 
zontal. 
May 11, at 10.20 A.M., we had a double shock. This was 
rather severe. Motion horizontal ; interval between shocks, 15 
seconds ; total duration, 25 seconds. 
May 28, at 10.30 P.M., a slight horizontal shock. 
Sept. 9, at 10.20 p.M., double, horizontal shock from N.E. ; 
interval !25 seconds. This was a more severe shock than we 
usually feel here. 
Nov. 12, at 5.10 A.M., a slight horizontal shock, 
Dec. 3, at 9.20 P.M., a slight horizontal shock, 
Jan. 2, 1873, at 7.40 A.M., a shock which, in these islands, is 
considered very severe. The motion was horizontal. The main 
undulation was followed by rapid oscillations for 45 seconds, 
followed by a sea-wave. tens 
I regret that I cannot give full and definite information re- 
specting this earthquake. I was away from home at the time, 
staying at the inland residence of the British Consul, on the 
island of Upolu, where I was unable to note with precision any 
of the accompanying phenomena. The Consul’s residence is a 
wooden building with a ground floor only. It stands due east 
and west. This shook very severely with the rapid undulations 
of the earth-waves, apparently, longitudinally from east to west. 
I at once'thought the centre of impulse was to the east of my 
position. Of this, however, I am by no means certain ; in fact, 
I have reason to doubt whether my observation on this point was 
correct. The sea-wave was almost entirely confined to the south 
coast of the islands of Upolu and Saraii. On the island of Tu- 
tuila (forty miles to the east of Upolu) it rose equally on the 
7 
NATURE 
325 
south and north sides. I have at present no information from 
Manua (three islands about sixty miles east of Tutuila) except 
that both earthquake and sea-wave were felt there. None of 
those who saw the sea-wave noticed particularly the time which 
elapsed between the earthquake and the rolling inland of the 
sea-wave, All my informants from Saraii (the most westerly 
island) agree that the one followed the other almost 
Immediately. They felt the earthquake and almost im- 
mediately afterwards saw the reef bare much lower than 
it is at low tide. The tide was at about halfebb at the 
time. Following closely on this efflux came the reflux in a large 
wave which rolled inland and flooded /the sites of villages lying 
low at the back of deep bays. This wave rose about 6 ft. above 
high-water mark during spring tides. ‘he rise and fall during 
spring tides in this group being about 4 ft. 6in. The first great 
wave was followed by a number of smaller waves, and the oscil~ 
lation continued for some time. No efflux of the sea was noticed, 
as far as I can learn, on Upolu or Tutuila. At the latter island 
the sea-wave rolled inland more than half-an-hour after the earth- 
quake, and 10 :e about 6 ft. above high-water mark. No damage 
of importance was done by the wave. 
Two days after the above earthquakes, we had three others in 
rapid succession, and three more have followed them on different 
days since, viz. :— 
On Jan. 4, at 10.45 A.M., we had a heavy horizontal shock, or 
rather a succession of shocks, two of which were severe. These 
continued 55 seconds, and were accompanied by great rumbling 
and a hissing noise. 
Four minutes afterwards, viz., at 10.50 A.M., we experienced 
another sharp shock, accompanied by similar noises. The 
vibrations of this shock continued 15 seconds. We had scarcely 
recovered our equilibrium and quieted our nerves after this second 
shock when, at 10.57 A.M., we were startled by another, the 
oscillations of which lasted 20 seconds. This also was accom- 
panied by great rumbling. 
No damage was done by these earthquakes, The buildings 
in these islands are all low, and nearly all are built with wood, 
so that only a very severe earthquake could do much injury. 
On Jan. 8-9, at midnight, another slight horizontal shock 
was felt. 
oon Jan. 13, at 8.45 A.M., we had another {which was also 
slight. 
: = Jan. 14, at 5.24 A.M., there was another slight horizontal 
shock. 
The Samoan Islands owe their existence to volcanoes, as they 
consist almost entirely of volcanic rock. There has, however, 
been no eruption for a very long period until in 1867, when, it 
will be remembered, a submarine volcano burst out between Tait 
and Olosenga, two of the Manua islands in the eastern end of 
the archipelago. This subsided after a fortnight’s activity. 
A few months afterwards I was on board H.M.S. Falcon when 
soundings were taken over the spot where the volcano had been. 
We found a cone 180 feet above the bed of the surrounding 
ocean: the average depth of the sea around it being 120 fathoms, 
while the depth on the apex of the cone was only go fathoms. 
There has been no further e:uption from this volcano up to the 
present time. Almost ever since this has been quiet, there has 
been great activity in the volcano of Nina Foou, in the neigh- 
bourhood of the Friendly group of islands. 
Samoa, S. Pacific 
THE ARITHMOMETER 
Is espe of our readers who have anything to do with 
calculations have heard of the above calculating 
machine, the invention of M. Thomas de Colmar. A few 
remarks, therefore, on its construction and operation may 
be of interest to those who have not seen this really useful 
calculating machine. 
The instrument is of small size, the one which we are 
about to describe being only 22 in. long, 64 in, wide, and 
34 in. deep. 
We can best give an idea of the great saving of time 
effected by this instrument when we state that with it 
eight figures (tens of millions) can be multiplied by eight 
figures in eighteen seconds, sixteen figures be divided by 
eight figures in twenty seconds, and a square root of six- 
teen figures be extracted, with the proof, in less than two 
minutes. 
Our illustration shows a top view of an arithmometer 
S. J. WHITMEE 
