Vol. XXV. No. 1.] 
.POPTJLAB SCIENCE NEWS. 
proximity to the object of my searcli. Viewed 
from the south side near tlie perpendicular ledge, 
it appeared like an excressence attached to the 
rocli some twenty feet high and extending out 
from it about sixteen feet. Viewed from the front 
it was, perhaps, more than twenty feet wide. Tlie 
form of it suggested tliat of a kiosk or pagoda 
built up agaiust the rock. It was covered with 
•green moss, and water in considerable quantity 
was running down over its roof and dropping 
I from its eaves in front of the recesses or alcoves 
that opened out from it. 
Entering the first and smallest recess at the 
south side, I found a hole a little larger than one's 
head had lieen knocked through a stone partition 
that constituted the back side of the recess, aud 
looking into it I saw an inclosed space large 
enough for two or three men to lie down in. 'i'here 
was a high and round door-step to the other two 
niches or alcoves, upon which the water was drop- 
ping, and it was only with much eflbrt and some 
wetting that I succeeded in getting in. There was 
no even floor, only good standing and sitting 
places, and near the roof at one end, a sludf of 
rock forming a nice basin filled with cool, spark- 
ling water from the spring. 
Looking out upon the broad, green river tlu'ough 
the dripping water that for an unknown period 
had lieen falling in front of the doorway, I natu- 
rally speculated on the questions as to who was 
the architect of this curious structure, and what 
was his building material, where did he get it, and 
how did he sliape it. As for the material, it was 
very different in appearance from the native lime- 
stone behind me. It was light colored, porous, and 
unstratified, appearing like dried mortar. Kvi- 
dently it was a deposit from the water of the spring, 
the deposition being occasioned by the warmth and 
light of day as it emerged from the dark recesses 
of the limestone. In this case the lime-laden water 
came out of a point in the precipice that leaned 
over beyond the perpendicular, and the growth of 
moss at its mouth helped the deposition from the 
petrifying water by att'ecting more surface. As 
the moss grew, so the deposit at its roots grew, 
producing finally the curious structure that we see 
this day. 
There are possible only two methods by which 
space is inclosed. One Is by hollowing out a solid 
, substance, as caves are often hollowed out by dis- 
solving waters in limestone regions. Another way- 
Is to suiTound a space with w alls and cover it 
with a' roof, as with ordinary human dwellings. It 
is very rarely that nature adopts the latter method 
as in this instance. Think of a house growing 
for hundreds of years without labor and witliout 
hands. 
Niagara Falls, Xov. 16, 1890. 
although unquestionaldy more than 1,500 years 
old, three or four axes retaining their fine cutting 
edges and still quite serviceable, a number of 
chisels and gouges of all shapes and sizes, ham- 
mers, adzes, saws, flies, etc. In the smith's 
department may be specified a brazier for 1)urning 
cliarcoal, quite complete, two or three anvils of 
different sizes and shapes, a fine paii- of tongs 
adapted for lifting crucibles, a curious tripod 
candelabrum lamp, or candle-stick, and several 
other curious objects the precise uses of which 
have not yet been determined. In addition there 
are several large bars of iron, a couple of plow- 
shares, and a broken sword. Probably more will 
be found deeper down in the well. This is un- 
doubtedly the most important find at Silchester 
since the discovery of the bronze Koman eagle, 
now at Strathfleldsaye, some years ago. 
A2ifTIQUITY OF THE CARPENTER'S PLANE. 
A VERY interesting discovery has been made at 
the Roman city of Silchester. The excavators 
came across a dry well, which, on l)eing explored, 
proved quite a little museum of antiquity. Some 
fifteen feet down, a Times correspondent says, the 
diggers found an urn-shaped pottery vase, about a 
foot in length, quite Intact, and, curiously enough, 
protected by himps of chalk built around it. 'ITie 
vase, which proljably originally contained some 
precious substance, was, however, quite empty. 
Above it were deposited a great number of iron 
implements, most of which were in a wonderful 
state of preservation. They seem to have been 
the tools of a carpenter and a coppersmith or 
silversmith, with some miscellaneous objects of 
blacksmith's work thrown in. The principal spec- 
imen is a carpenter's plane of quite modern type, 
WHERE PUMICE STONE COMES FROM. 
We often hear it remarked, and particularly 
after an eruption of a volcano, that pumice stone 
ought to be plei.tif ul and cheap, as quantities must 
have been ejected during the volcanic disturbance. 
As a matter of fact, however, none of the white 
stone in general use is obtained from active volca- 
noes. It comes from deposits of the article dis- 
covered in one or two quarters of the globe, the 
best of W'hich is at present to be found in the 
island of Lipari, situated in the Tyrrhenian sea. 
The island is mountainous in character, and con- 
sists of tuffs and lavas and of highly siliceous vol- 
canic products. The district where the stone is 
found is called Campo Bianco or Monte Petalo 
(1500 feet above the level of the sea). 
After riding a considerable distance, partly 
along precipitous paths sufllciently dangerous to 
be interesting, an<l partly through vineyards and 
over grassy plains, one almost suddenly comes 
upon a seemingly snow-clad narrow valley enclosed 
l)y hilLs, also quite white, and the whole glaringly 
bright on a sunny day. Into these hills workmen 
are ceaselessly digging deep burrows, working 
within by candle light. In their excavations they 
come across many lumps of pumice stone, which 
are placed in baskets, subsequently being conveyed 
along the valley to the seashore, where small 
boats are loaded and sailed to the seaport near by, 
where the stone is sorted, packed, and sliipped to 
distant parts, either via Messina or I>eghoru. — 
Manufacturer and Builder. 
<#» 
Magnificent Railroad Construction. — A 
comiriercial traveller, who has just returned from 
Mexico, reports that he was much struck with the 
magnificent construction of the Mexican Gulf 
Railway. The sleepers are of sound mahogany, 
and many of the bridges and culverts are, he says, 
built of white marble. Though this might appear, 
at first sight, to be lavish extravagance, the con- 
tractors have found the employment of these sub- 
stances to l)e economical, as both mahogany and 
marble exist in the country traversed by the line. 
Printing a Newspaper with a Steam Road 
Roller. — An incident occurred a few days ago 
which may be cited as an example of fertility of 
resource in emergency. It appears that, owing to 
an accident at the gas works, the town of Middles- 
brough (England) was deprived of gas for all pur 
poses. This did not reach the ears of the managei 
of the North-Eastern Daily Gazette until 10 o'clock 
but a novel idea was evolved and promptly acted 
ujjon. A gang of men was hastily obtained from 
neighboring works, and heavy iron plates were 
laid in tlie Grand Hotel yard, adjoining the print- 
ing-machine room, through the wall of which a 
large aperture was made. A 15-ton steam road 
roller was then got into position, shored and rap- 
idly geared, and on(^ hour only after the ordinary 
time of starting, the printing machine l)egan work, 
the issue of 64,000 copies being produced without 
a single hitch in the unique manner described. 
INDUSTRIAL MEMORANDA. 
Pneumatic Chisel.— Messrs. E. de Buehler & 
Co., Berlin, Germany, have, according to L'indus- 
trie moderne, introduced in their stone-cutting es- 
tablishment a pneumatic chisel. The apparatus 
resembles in appearance a syringe which the 
operator holds with both hands, and as he lets it 
slide over tlie_ surface of the stone or metal, the 
chisel chips oft' splinters and particles. Com- 
pressed air acting on a piston imparts to the chisel 
a rotation of from 10,000 to 12,000 revolutions per 
minute. 
A crack in a piece of metal is prevented from 
extending further by the well-known means of 
drilling a hole where the rent ends ; but when the 
hole is not bored on just that spot, the crack is apt 
to continue beyond the hole. To faciliate the 
search of the exact point, Bevue Industrielle recom- 
mends moistening the cracked surface with pe- 
troleum, then wipe it, and then immediately rub it 
with chalk. The oil that has penetrated into the 
crack exudes and thus indicates with precision 
where the crack stops. 
SCIENTIFIC BREVITIES. 
Great Advance in Platinum. — According to 
Russian advices, the whole of the platinum which 
will lie produced in the Ural mines for the next ten 
years has been sold in advance to certain foreign 
companies. Owing to these contracts the price of 
platinum has advanced to about $20.00 per ounce. 
Luminous Crayon. — Mr. Cecil Carus-Wilson 
writes to Nature that he has invented a luminous 
crayon for the purpose of enabling lecturers to 
draw on the blackboard when the room is dark- 
ened for the use of the lantern. He hopes that the 
invention may prove of value not only to lecturers 
who use a lantern, but also (in another form) to 
those students who wish to take notes. 
Electrical Conduction. — The idea that elec- 
tricity flows through a wire somewhat as water 
flows throgli a pipe is likely to pass away, as 
reasons appear for believing that the energy is 
not transmitted by the wire at all, but by the 
surrounding ether. In some experiments by 
Professor J. J. Thompson, the velocity of electric 
disturbances along the wire surrounded by air was 
nearly double the velocity along the same wire 
surrounded by sulphur, and the velocity of the 
discharge through a vacuum tube fifty feet long 
was comparable with that of light. The conclusion 
is that the conductor merely guides the discharge 
impelled through the ether. 
The Utilization of Niagara Falls.— The 
Cataract Construction Company, organized for the 
utilization of the water power, has decided to con- 
struct a tunnel of 490 square feet section on a 
slope of 7 feet in 1,000. The form is rectangular, 
with a semi-circular arched roof ; the width of the 
tunnel is 18 feet, height from bottom to spring of 
arch 19.485 feet, arched roof 9 feet radius, with 
floor concave to a radius of 41 feet, being one 
foot deep in the center. The bottom of the tunnel 
where it discharges into the lower river will be 20 
feet below average water height, so that only the 
arched i-oof will be shown above the water of the 
river. It is estimated that the velocity of the 
water in the tunnel will be over 25 feet per 
second. 
