Scientific American Supplement, No. 460, October 25, 1884 by Various

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[Illustration: APPARATUS FOR ESTIMATING THE CARBONIC ACID OF THE AIR.
FIG. 1.--Montsouris Apparatus. FIG. 2.--Smith's Minimetric Apparatus. FIG.
3.--Bertin-Sans Apparatus. FIG. 4.--Bubbling Glass. FIG. 5.--Pipette. FIG.
6.--Arrangement of the U-shaped Tube. FIG. 7.--Wolpert's Apparatus.]

Hygienists have for some years striven to obtain some very simple apparatus
(rather as an indicator than an analytical instrument) that should permit
it to be quickly ascertained whether the degree of impurity of a place was
incompatible with health, and in what proportion it was so. It is from such
efforts that have resulted the processes of Messrs. Smith. Lunge,
Bertin-Sans, and the apparatus of Prof. Wolpert (Fig. 7).

It is of the highest interest to ascertain the proportion of carbonic acid
in the air, and especially in that of inhabited places, since up to the
present this is the best means of finding out how much the air that we are
breathing is polluted, and whether there is sufficient ventilation or not.
Experiment has, in fact, demonstrated that carbonic acid increases in the
air of inhabited rooms in the same way as do those organic matters which
are difficult of direct estimation. Although a few ten-thousandths more of
carbonic acid in our air cannot of themselves endanger us, yet they have on
another hand a baneful significance, and, indeed, the majority of
hygienists will not tolerate more than six ten-millionths of this element
in the air of dwellings, and some of them not more than five
ten-millionths.

Carbonic acid readily betrays its presence through solutions of the
alkaline earths such as baryta and chalk, in which its passage produces an
insoluble carbonate, and consequently makes the liquid turbid. If, then,
one has prepared a solution of baryta or lime, of which a certain volume is
made turbid by the passage of a likewise known volume of CO_{2}, it will be
easy to ascertain how much CO_{2} a certain air contains, from the volume
of the latter that it will be necessary to pass through the basic solution
in order to obtain the amount of turbidity that has been taken as a
standard. The problem consists in determining the minimum of air required
to make the known solution turbid. Hence the name "minimetric estimation,"
that has been given to this process. Prof. Lescoeur has had the goodness to
construct for me a Smith's minimetric apparatus (Fig. 2) with the ingenious
improvements that have been made in it by Mr. Fischli, assistant to Prof.
Weil, of Zurich. I have employed it frequently, and I use it every year in
my lectures. I find it very practical, provided one has got accustomed to
using it. It is, at all events, of much simpler manipulation than that of
Bertin-Sans, although the accuracy of the latter may be greater (Figs. 3,
4, 5, and 6). But it certainly has more than one defect, and some of the
faults that have been found with it are quite serious. The worst of these
consists in the difficulty of catching the exact moment at which the
turbidity of the basic liquid is at the proper point for arresting the
operation. In addition to this capital defect, it is regrettable that it is
necessary to shake the flask that contains the solution after every
insufflation of air, and also that the play of the valves soon becomes
imperfect. Finally, Mr. Wolpert rightly sees one serious drawback to the
use of baryta in an apparatus that has to be employed in schools, among
children, and that is that this substance is poisonous. This gentleman
therefore replaces the solution of baryta by water saturated with lime,
which costs almost nothing, and the preparation of which is exceedingly
simple. Moreover, it is a harmless agent.

The apparatus consists of two parts. The first of these is a glass tube
closed at one end, and 12 cm. in length by 12 mm. in diameter. Its bottom
is of porcelain, and bears on its inner surface the date 1882 in black
characters. Above, and at the level that corresponds to a volume of three
cubic centimeters, there is a black line which serves as an invariable
datum point. A rubber bulb of twenty-eight cubic centimeters capacity is
fixed to a tube which reaches its bottom, and is flanged at the other
extremity (Fig. 7).

The operation is as follows:

The saturated, but limpid, solution of lime is poured into the first tube
up to the black mark, the tube of the air bulb is introduced into the lime
water in such a way that its orifice shall be in perfect contact with the
bottom of the other tube, and then, while the bulb is held between the fore
and middle fingers of the upturned hand, one presses slowly with the thumb
upon its bottom so as to expel all the air that it contains. This air
enters the lime-water bubble by bubble. After this the tube is removed from
the water, and the bulb is allowed to fill with air, and the same maneuver
is again gone through with. This is repeated until the figures 1882, looked
at from above, cease to be clearly visible, and disappear entirely after
the contents of the tube have been vigorously shaken.

The measures are such that the turbidity supervenes at once if the air in
the bulb contains twenty thousandths of CO_{2}. If it becomes necessary to
inject the contents of the bulb into the water twice, it is clear that the
proportion is only ten thousandths; and if it requires ten injections the
air contains ten times less CO_{2} than that having twenty thousandths, or
only two per cent. A table that accompanies the apparatus has been
constructed upon this basis, and does away with the necessity of making
calculations.

An air that contained ten thousandths of CO_{2}, or even five, would be
almost as deleterious, in my opinion, as one of two per cent. It is of no
account, then, to know the proportions intermediate to these round numbers.
Yet it is possible, if the case requires it, to obtain an indication
between two consecutive figures of the scale by means of another bulb whose
capacity is only half that of the preceding. Thus, two injections of the
large bulb, followed by one of the small, or two and a half injections,
correspond to a richness of 8 thousandths of CO_{2}; and 51/2 to 3.6
thousandths. This half-bulb serves likewise for another purpose. From the
moment that the large bulb makes the lime-water turbid with an air
containing two per cent. of CO_{2}, it is clear that the small one can
cause the same turbidity only with air twice richer in CO_{2}, _i.e._, of
four per cent.

This apparatus, although it makes no pretensions to extreme accuracy, is
capable of giving valuable information. The table that accompanies it is
arranged for a temperature of 17 deg. and a pressure of 740 mm. But different
meteorological conditions do not materially alter the results. Thus, with
10 deg. less it would require thirty-one injections instead of thirty, and
CO_{2} would be 0.64 per 1,000 instead of 0.66; and with 10 deg. more, thirty
injections instead of thirty one.

The apparatus is contained in a box that likewise holds a bottle of
lime-water sufficient for a dozen analyses, the table of proportions of
CO_{2}, and the apparatus for cleaning the tubes. The entire affair is
small enough to be carried in the pocket.--_J. Arnould, in Science et
Nature_.

* * * * *

[NATURE.]

THE VOYAGE OF THE VETTOR PISANI.

Knowing how much _Nature_ is read by all the naturalists of the world, I
send these few lines, which I hope will be of some interest.

The Italian R.N. corvette Vettor Pisani left Italy in April, 1882, for a
voyage round the world with the ordinary commission of a man-of-war. The
Minister of Marine, wishing to obtain scientific results, gave orders to
form, when possible, a marine zoological collection, and to carry on
surveying, deep-sea soundings, and abyssal thermometrical measurements. The
officers of the ship received their different scientific charges, and Prof.
Dohrn, director of the Zoological Station at Naples, gave to the writer
necessary instructions for collecting and preserving sea animals.

At the end of 1882 the Vettor Pisani visited the Straits of Magellan, the
Patagonian Channels, and Chonos and Chiloe islands; we surveyed the Darwin
Channel, and following Dr. Cuningham's work (who visited these places on
board H.M.S. Nassau), we made a numerous collection of sea animals by
dredging and fishing along the coasts.

While fishing for a big shark in the Gulf of Panama during the stay of our
ship in Taboga Island, one day in February, with a dead clam, we saw
several great sharks some miles from our anchorage. In a short time several
boats with natives went to sea, accompanied by two of the Vettor Pisani's
boats.

Having wounded one of these animals in the lateral part of the belly, we
held him with lines fixed to the spears; he then began to describe a very
narrow curve, and irritated by the cries of the people that were in the
boats, ran off with a moderate velocity. To the first boat, which held the
lines just mentioned, the other boats were fastened, and it was a rather
strange emotion to feel ourselves towed by the monster for more than three
hours with a velocity that proved to be two miles per hour. One of the
boats was filled with water. At last the animal was tired by the great loss
of blood, and the boats assembled to haul in the lines and tow the shark on
shore.

With much difficulty the nine boats towed the animal alongside the Vettor
Pisani to have him hoisted on board, but it was impossible on account of
his colossal dimensions. But as it was high water we went toward a sand
beach with the animal, and we had him safely stranded at night.

With much care were inspected the mouth, the nostrils, the ears, and all
the body, but no parasite was found. The eyes were taken out and prepared
for histological study. The set of teeth was all covered by a membrane that
surrounded internally the lips; the teeth are very little, and almost in a
rudimental state. The mouth, instead of opening in the inferior part of the
head, as in common sharks, was at the extremity of the head; the jaws
having the same bend.

Cutting the animal on one side of the backbone we met (1) a compact layer
of white fat 20 centimeters deep; (2) the cartilaginous ribs covered with
blood vessels; (3) a stratum of flabby, stringy, white muscle, 60
centimeters high, apparently in adipose degeneracy; (4) the stomach.

By each side of the backbone he had three chamferings, or flutings, that
were distinguished by inflected interstices. The color of the back was
brown with yellow spots that became close and small toward the head, so as
to be like marble spots. The length of the shark was 8.90 m. from the mouth
to the _pinna caudalis_ extremity, the greatest circumference 6.50 m., and
2.50 m. the main diameter (the outline of the two projections is made for
giving other dimensions).

The natives call the species _Tintoreva_, and the most aged of the village
had only once before fished such an animal, but smaller. While the animal
was on board we saw several _Remora_ about a foot long drop from his mouth;
it was proved that these fish lived fixed to the palate, and one of them
was pulled off and kept in the zoological collection of the ship.

The Vettor Pisani has up the present visited Gibraltar, Cape Verde Islands,
Pernambuco, Rio Janeiro, Monte Video, Valparaiso, many ports of Peru,
Guayaquil, Panama, Galapagos Islands, and all the collections were up to
this sent to the Zoological Station at Naples to be studied by the
naturalists. By this time the ship left Callao for Honolulu, Manila, Hong
Kong, and, as the Challenger had not crossed the Pacific Ocean in these
directions, we made several soundings and deep-sea thermometrical
measurements from Callao to Honolulu. Soundings are made with a steel wire
(Thompson system) and a sounding-rod invented by J. Palumbo, captain of the
ship. The thermometer employed is a Negretti and Zambra deep-sea
thermometer, improved by Captain Maguaghi (director of the Italian R.N.
Hydrographic Office).

With the thermometer wire has always been sent down a tow-net which opens
and closes automatically, also invented by Captain Palumbo. This tow-net
has brought up some little animals that I think are unknown.

G. CHIERCHIA.

Honolulu July 1.

The shark captured by the Vettor Pisani in the Gulf of Panama is _Rhinodon
typicus_, probably the most gigantic fish in existence. Mr. Swinburne Ward,
formerly commissioner of the Seychelles, has informed me that it attains to
a length of 50 feet or more, which statement was afterward confirmed by
Prof. E.P. Wright. Originally described by Sir A. Smith from a single
specimen which was killed in the neighborhood of Cape Town, this species
proved to be of not uncommon occurrence in the Seychelles Archipelago,
where it is known by the name of "Chagrin." Quite recently Mr. Haly
reported the capture of a specimen on the coast of Ceylon. Like other large
sharks (_Carcharodon rondeletii, Selache maxima_, etc.), Rhinodon has a
wide geographical range, and the fact of its occurrence on the Pacific
coast of America, previously indicated by two sources, appears now to be
fully established. T. Gill in 1865 described a large shark known in the
Gulf of California by the name of "Tiburon ballenas" or whale-shark, as a
distinct genus--_Micristodus punctatus_--which, in my opinion, is the same
fish. And finally, Prof. W. Nation examined in 1878 a specimen captured at
Callao. Of this specimen we possess in the British Museum a portion of the
dental plate. The teeth differ in no respect from those of a Seychelles
Chagrin; they are conical, sharply pointed, recurved, with the base of
attachment swollen. Making no more than due allowance for such variations
in the descriptions by different observers as are unavoidable in accounts
of huge creatures examined by some in a fresh, by others in a preserved,
state, we find the principal characteristics identical in all these
accounts, viz.: the form of the body, head, and snout, relative
measurements, position of mouth, nostrils, and eyes, dentition, peculiar
ridges on the side of the trunk and tail, coloration, etc. I have only to
add that this shark is stated to be of mild disposition and quite harmless.
Indeed, the minute size of its teeth has led to the belief in the
Seychelles that it is a herbivorous fish, which, however, is not probable.

ALBERT GUNTHER.

Natural History Museum, _July 30_.

* * * * *

THE GREELY ARCTIC EXPEDITION.

[Illustration: THE GREELY ARCTIC EXPEDITION.--THE FARTHEST POINT NORTH.]

Some account has been given of the American Meteorological Expedition,
commanded by Lieutenant, now Major, Greely, of the United States Army, in
the farthest north channels, beyond Smith Sound, that part of the Arctic
regions where the British Polar expedition, in May, 1876, penetrated to
within four hundred geographical miles of the North Pole. The American
expedition, in 1883, succeeded in getting four miles beyond, this being
effected by a sledge party traveling over the snow from Fort Conger, the
name they had given to their huts erected on the western shore near
Discovery Cove, in Lady Franklin Sound. The farthest point reached, on May
18, was in latitude 83 deg. 24 min. N.; longitude 40 deg. 46 min. W., on
the Greenland coast. The sledge party was commanded by Lieutenant Lockwood,
and the following particulars are supplied by Sergeant Brainerd, who
accompanied Lieutenant Lockwood on the expedition. During their sojourn in
the Arctic regions the men were allowed to grow the full beard, except
under the mouth, where it was clipped short. They wore knitted mittens, and
over these heavy seal-skin mittens were drawn, connected by a tanned
seal-skin string that passed over the neck, to hold them when the hands
were slipped out. Large tanned leather pockets were fastened outside the
jackets, and in very severe weather jerseys were sometimes worn over the
jackets for greater protection against the intense cold. On the sledge
journeys the dogs were harnessed in a fan-shaped group to the traces, and
were never run tandem. In traveling, the men were accustomed to hold on to
the back of the sledge, never going in front of the team, and often took
off their heavy overcoats and threw them on the load. When taking
observations with the sextant, Lieutenant Lockwood generally reclined on
the snow, while Sergeant Brainerd called time and made notes, as shown in
our illustration. When further progress northward was barred by open water,
and the party almost miraculously escaped drifting into the Polar sea,
Lieutenant Lockwood erected, at the highest point of latitude reached by
civilized man, a pyramidal-shaped cache of stones, six feet square at the
base, and eight or nine feet high. In a little chamber about a foot square
half-way to the apex, and extending to the center of the pile, he placed a
self-recording spirit thermometer, a small tin cylinder containing records
of the expedition, and then sealed up the aperture with a closely fitting
stone. The cache was surmounted with a small American flag made by Mrs.
Greely, but there were only thirteen stars, the number of the old
revolutionary flag. From the summit of Lockwood Island, the scene presented
in our illustration, 2,000 feet above the sea, Lieutenant Lockwood was
unable to make out any land to the north or the northwest. "The awful
panorama of the Arctic which their elevation spread out before them made a
profound impression upon the explorers. The exultation which was natural to
the achievement which they found they had accomplished was tempered by the
reflections inspired by the sublime desolation of that stern and silent
coast and the menace of its unbroken solitude. Beyond to the eastward was
the interminable defiance of the unexplored coast--black, cold, and
repellent. Below them lay the Arctic Ocean, buried beneath frozen chaos. No
words can describe the confusion of this sea of ice--the hopeless asperity
of it, the weariness of its torn and tortured surface. Only at the remote
horizon did distance and the fallen snow mitigate its roughness and soften
its outlines; and beyond it, in the yet unattainable recesses of the great
circle, they looked toward the Pole itself. It was a wonderful sight, never
to be forgotten, and in some degree a realization of the picture that
astronomers conjure to themselves when the moon is nearly full, and they
look down into the great plain which is called the Ocean of Storms, and
watch the shadows of sterile and airless peaks follow a slow procession
across its silver surface."--_Illustrated London News_.

* * * * *

THE NILE EXPEDITION.

[Illustration: WHALER GIG FOR THE NILE.]

As soon as the authorities had finally made up their minds to send a
flotilla of boats to Cairo for the relief of Khartoum, not a moment was
lost in issuing orders to the different shipbuilding contractors for the
completion, with the utmost dispatch, of the 400 "whaler-gigs" for service
on the Nile. They are light-looking boats, built of white pine, and weigh
each about 920 lb., that is without the gear, and are supposed to carry
four tons of provisions, ammunition, and camp appliances, the food being
sufficient for 100 days. The crew will number twelve men, soldiers and
sailors, the former rowing, while the latter (two) will attend the helm.
Each boat will be fitted with two lug sails, which can be worked reefed, so
as to permit an awning to be fitted underneath for protection to the men
from the sun. As is well known, the wind blows for two or three months
alternately up and down the Nile, and the authorities expect the flotilla
will have the advantage of a fair wind astern for four or five days at the
least. On approaching the Cataracts, the boats will be transported on
wooden rollers over the sand to the next level for relaunching.

* * * * *

THE PROPER TIME FOR CUTTING TIMBER.

_To the Editor of the Oregonian:_

Believing that any ideas relating to this matter will be of some interest
to your readers in this heavily-timbered region, I therefore propose giving
you my opinion and conclusions arrived at after having experimented upon
the cutting and use of timber for various purposes for a number of years
here upon the Pacific coast.

This, we are all well aware, is a very important question, and one very
difficult to answer, since it requires observation and experiment through a
course of many years to arrive at any definite conclusion; and it is a
question too upon which even at the present day there exists a great
difference of opinion among men who, being engaged in the lumber business,
are thereby the better qualified to form an opinion.

Many articles have been published in the various papers of the country upon
this question for the past thirty years, but in all cases an opinion only
has been given, which, at the present day, such is the advance and higher
development of the intellectual faculties of man, that a mere opinion upon
any question without sufficient and substantial reasons to back it is of
little value.

My object in writing this is not simply to give an opinion, but how and the
methods used by which I adopted such conclusions, as well also as the
reasons why timber is more durable and better when cut at a certain season
of the year than when cut at any other.

In the course of my investigations of this question for the past thirty
years, I have asked the opinion of a great many persons who have been
engaged in the lumber business in various States of the Union, from Maine
to Wisconsin, and they all agree upon one point, viz., that the winter time
is the proper time for cutting timber, although none has ever been able to
give a reason why, only the fact that such was the case, and therefore
drawing the inference that it was the proper time when timber should be
cut; and so it is, for one reason only, however, and that is the
convenience for handling or moving timber upon the snow and ice.

It was while engaged in the business of mining in the mountains of
California in early days, and having occasion to work often among timber,
in removing stumps, etc., it was while so engaged that I noticed one
peculiar fact, which was this--that the stumps of some trees which had been
cut but two or three years had decayed, while others of the same size and
variety of pine which had been cut the same year were as sound and firm as
when first cut. This seemed strange to me, and I found upon inquiry of old
lumbermen who had worked among timber all their lives, that it was strange
to them also, and they could offer no explanation; and it was the
investigation of this singular fact that led me to experiment further upon
the problem of cutting timber.

It was not, however, until many years after, and when engaged in clearing
land for farming purposes, that I made the discovery why some stumps should
decay sooner than others of the same size and variety, even when cut a few
months afterward.

I had occasion to clear several acres of land which was covered with a very
dense growth of young pines from two to six inches in diameter (this work
for certain reasons is usually done in the winter). The young trees, not
being suitable for fuel, are thrown into piles and burned upon the ground.
Such land, therefore, on account of the stumps is very difficult to plow,
as the stumps do not decay for three or four years, while most of the
larger ones remain sound even longer.

But, for the purpose of experimenting, I cleaned a few acres of ground in
the spring, cutting them in May and June. I trimmed the poles, leaving them
upon the ground, and when seasoned hauled them to the house for fuel, and
found that for cooking or heating purposes they were almost equal to oak;
and it was my practice for many years afterward to cut these young pines in
May or June for winter fuel.

I found also that the stumps, instead of remaining sound for any length of
time, decayed so quickly that they could all be plowed up the following
spring.

From which facts I draw these conclusions: that if in the cutting of timber
the main object is to preserve the stumps, cut your trees in the fall or
winter; but if the value of the timber is any consideration, cut your trees
in the spring after the sap has ascended the tree, but before any growth
has taken place or new wood has been formed.

I experimented for many years also in the cutting of timber for fencing,
fence posts, etc., and with the same results. Those which were cut in the
spring and set after being seasoned were the most durable, such timber
being much lighter, tougher, and in all respects better for all variety of
purposes.

Having given some little idea of the manner in which I experimented, and
the conclusions arrived at as to the proper time when timber should be cut,
I now propose to give what are, in my opinion, the reasons why timber cut
in early summer is much better, being lighter, tougher and more durable
than if cut at any other time. Therefore, in order to do this it is
necessary first to explain the nature and value of the sap and the growth
of a tree.

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