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Scientific American Supplement, No. 520, December 19, 1885 online

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may be, in order that the claw may be raised sufficiently with only a
small movement of the short arm of the lever. Of course, the shorter the
arm is, the more accurately the lid and pin must be made to close.

If the pin, pressing short arm down, be too short, the pressure will not
be enough to release the claw, and consequently the performer might find
himself really unable to get out of the box after it is locked.

The end of the lever should be finished with a wood block, as Fig. 6,
larger than the pin on the lid, as represented by L and M, Fig. 3.

The block may be of other material, but should be colored the same as the
wood the box is made of, so that, if any one were to look down on it, no
suspicion would be aroused, as might be were plain brass used.

[Illustration: FIG 4.]

[Illustration: FIG 5.]

In Fig. 5, I show an easy way of hanging the lever. It is simply a piece
of wire sharpened and notched, so as to form several small barbs,
preventing withdrawal. The mode of fixing will be easily understood by
reference to B and C, Fig. 5. Some considerable amount of care will have
to be bestowed on fitting and adjusting this part of the work, on which
the successful performance of the trick consists, and before finally
fixing up, it should be ascertained that all the movements work
harmoniously. It will be best to cut the groove in which the lever works
from below, and, after the lever is fixed, to fill up the space not
required by the lever with strips of wood, H, H. If preferred, the space
can be shaped out from the back, i.e., the inside of the framing, and
then filled where not required, but as this, however neatly done, would
show a joint which might be detected by sharp eyes, it is better to cut
from below, though more troublesome.

The end containing the movable panel being arranged, make up the rest of
the box to it, taking care to make the rebates of the top and bottom
frames to correspond with those of the end.

The other panels should not, however, depend on the grooves on two sides
only, but at tops and bottoms as well.

[Illustration: FIG. 6.]

[Illustration: FIG. 7. & FIG. 8.]

[Illustration: FIG. 9.]

The rebates are to be cut only to have all the framing inside look alike;
and as the panel, B, is made to fit quite close into the rebate, it will
not be surmised that it is not fitted in the usual way.

After the box is made and fitted together, the clamping must be done. The
only necessity for this is in order that the bolt, D, which we have seen
is made on the outside end exactly to match the screws used to fasten the
clamps, should not be conspicuous, as it would be were it alone. As it
is, it will not be specially observable, being apparently only one of the
screws to fasten the clamps.

The clamps may be of thin brass or iron, shaped as shown at Fig. 9. One
of the corner holes must be arranged to cover D exactly, and the others
regulated to it. Let us suppose that A, Fig. 9, is the one through which
the bolt goes; the other corner screw holes must be equally distant from
the edges of the clamps. Twelve of these clamps will be needed. After
they have been screwed on, put the bolt through, and let the claw of the
lever hold it in place. Then mark and cut the bolt flush with the clamp,
making a hollow on the end of it to imitate the screws, as D, Fig. 4. The
other end of the bolt should either be made flush with the inside of
frame and colored to match it, or, better, cut short and faced flush with
a piece of wood to match the framing.

If a piece of wood with a knot be chosen for this side of the frame, so
much the better. Immediately over the hole, L, a wooden pin should be
fixed in the lid, and of such length that it will press the short arm of
lever down sufficiently. It should fit the hole pretty closely.

At the other end, a corresponding pin and hole should be made, and, say,
two along the front. These will then look as if they were intended merely
as fittings to hold the lid in position. The lid at the other end of the
box from the movable panel should have a stop of some sort; the ordinary
brass joint stop will do as well as any, and should be strong. The reason
for placing it at what I may call "the other end" is that, when the box
is being examined, it will attract notice, and draw attention from the
movable panel end.

We may now finally adjust the loose panel, which must fit tight at top
and bottom, and be slightly beveled, as shown on section. Two holes must
also be cut through it, at such a distance from each other that a finger
and thumb can be put through them, so as to allow of the panel being
moved. In the deep grooving in front also put a couple of springs, say
pieces of clock springs, as shown, I, I, Fig, 2. These serve to assist
the bolt, D, by pushing the panel into position.

Holes to match those in end panel must also be cut in the other panels,
and when a lock, preferably a padlock, has been fitted, the box is
complete.

I don't know whether it is necessary to say that the lid should be hinged
at the back, and of course it will add to the appearance of the box if it
be polished or oiled.

Now, for those who may not have seen the locked and corded box trick
performed, a few words of caution may not be out of place. Don't forget
to have something in a pocket easily got at that will serve to push the
bolt out, before going into the box. A piece of stout wire, a small
pencil case, or anything of that sort will do. Be careful when getting
into the box to lie with your head toward the loose panel end, and face
toward the front - as there will be no space to turn round; the right hand
will then be uppermost and free to push the bolt out. Having done this,
grasp the panel with the finger and thumb by means of the two holes, push
it to the front of the box, when the back edge will be clear of the
groove. It can now easily be pulled into the box, and the performer can
creep out. When out, refix panel and bolt so that everything looks as it
was. Any cording that may be over the end of the box will give
sufficiently to allow of exit.

I have, I think, made it quite clear that padlock and ropes have nothing
to do with the real performance of the trick, but they serve to mystify
spectators, who may be allowed to knot the rope and seal the knots in any
way they choose.

There must always be a screen or curtain to hide the box from the
spectators while the performer is getting in or out. - _D.B. Adamson, in
Amateur Work._

* * * * *




PRICES OF METALS.


The _Metallarbeiter_ remarks that metals have in most cases experienced a
reduction in value of late years, this depreciation being attributed in
some measure to the cheaper methods of obtaining metals as well as to the
discovery of new sources of mineral wealth.

The following comparative table shows the approximate prices of various
metals in December, 1874, and December, 1884:

Dec., 1874. Dec., 1884.
Per lb. Per lb.
£ s d. £ s. d.
Osmium 71 10 0 62 0 0
Iridium 70 0 0 45 0 0
Gold 62 15 0 63 0 0
Platinum 25 7 6 21 7 6
Thallium 23 17 6 4 15 0
Magnesium 10 5 0 1 15 0
Potassium 5 0 0 4 0 0
Silver 3 17 6 (in Hamburg) 3 7 6
Aluminum 1 16 0 1 16 0
Cobalt 1 14 0 1 2 0
Sodium 0 14 2 0 8 8
Nickel 0 11 0 0 3 1
Bismuth 0 8 1 0 8 1
Cadmium 0 7 1 0 4 0
Quicksilver 0 2 0 (in London) 0 1 9
Tin 0 1 1 (in Berlin) 0 0 9
Copper 0 0 10 (" " ) 0 0 7
Arsenic 0 0 8 0 0 4-1/2
Antimony 0 0 6-1/4 (" " ) 0 0 5
Lead 0 0 2-3/4 (" " ) 0 0 1-3/8
Zinc 0 0 2-1/2 (" " ) 0 0 1-3/4
Steel 0 0 1-3/8 ( in 0 0 0-3/4
Bar iron 0 0 1-1/8 Upper 0 0 0-5/8
Pig iron 0 0 0-7/16 Silesia ) 0 0 0-1/4

Gold now ranks highest in value of all metals, the competition of osmium
and iridium having been over come. It is only by reason of improved
methods of preparation that the latter have become cheaper, while their
use has at the same time increased. Iridium is mixed with platinum in
order to increase its strength and durability. The normal standards of
the metrical system are made of platinum-iridium on account of its known
immutabilty. In 1882, platinum stood 15 per cent. below its present
value; but its increased employment for industrial purposes led to the
subsequent improvement in price. Thallium has experienced a severe
depreciation on account of the economical process by which it is
extracted from the residue of the lead chambers used in the manufacture
of sulphuric acid. The use of this metal is mainly confined to
experimental purposes. The fall in silver has arisen from increased
production and diminished use for coinage.

Magnesium was scarcely of any industrial value prior to the fall in price
now recorded. Improved processes for its treatment have successfully
engaged the attention of scientific men, and it is now capable of being
used as an alloy with other metals. The Salindres factory regulates the
price to a certain extent, and its system of working is regarded as a
guide in the various processes connected with this branch of industry.
The manufacture of potassium and sodium will, it is expected, be more
fully elucidated than hitherto, by means of researches made at Schering's
Charlottenburg factory. The course of nickel prices illustrates the
stimulus to economical production afforded by an increased consumption.
This latter fact is principally due to the employment of nickel for
coinage, as alloy for alfenide, etc. The use of cadmium is materially
restricted by its relatively limited supply. Hitherto, its only source
was in the incidental products of zinc distillation, but of late it has
been attempted to bring it into solution from its oxide combinations. An
increased employment of cadmium for industrial purposes is expected to
follow.

Production in excess of the demand has caused the depreciation recorded
in tin, and various other metals not commented upon, this remark applying
even to the scarce metals, arsenic and antimony. Even the better marks of
Cornwall tin and Mansfield refined copper have had to follow the downward
course of the market.

* * * * *




A PERPETUAL CALENDAR.


The annexed figure represents a perpetual calendar, which any one can
construct for himself, and which permits of finding the day that
corresponds to a given date, and conversely.

The apparatus consists of a certain number of circles and arcs of circles
divided by radii. The ring formed by the two last internal circles is
divided into 28 equal parts, which bear the names of the week, the first
seven letters of the alphabet in reversed order, and two signs X. The
circle formed by the external circumference of the ring constitutes the
movable part of the apparatus, and revolves around its center. Two
circular sectors, which are diametrically opposite, are each divided into
seven parts and constitute the fixed portions. In the divisions of the
upper sector are distributed the months, according to the order of the
monthly numbers. In the other sector the days of the month are regularly
distributed. In order to render the affair complete, a table is arranged
upon the movable disk for giving the annual numbers, or rather, in this
case, the annual letters. The calendar is used as follows: Say, for
example, we wish to find what days correspond to the different dates of
August, 1885; we look in the table for the letter (D) that corresponds to
this year; then we bring this letter under the given month (August) and
the days marked upon the movable disk corresponding to the dates sought,
and it only remains to make a simple reading.

[Illustration: PERPETUAL CALENDAR.]

It will be seen that the leap-years correspond to two letters. We here
employ the first to Feb. 29 inclusive, and the second for the balance of
the year. The calendar may be made of cardboard, and be fixed to
wood. - _La Nature._

* * * * *




AN ACCOMPLISHED PARROT.


Around the door of a Sixth Ave. bird store near Twenty-third St. was
gathered the other day a crowd so large that it was a work of several
minutes to gain entrance to the interior. From within there proceeded a
hoarse voice dashed with a suspicion of whisky, which bellowed in
Irish-American brogue the enlivening strains of "Peek-a-boo." With each
reiteration of "Peek-a-boo" the crowd hallooed with delight, and one
small boy, in the exuberance of his joy, tied himself into a sort of knot
and rolled on the pavement. Suddenly the inebriated Irishman came to a
dead stop, and another voice, pleasanter in quality, sang the inspiring
national ode of "Yankee Doodle," followed by the stentorian query and
answer all in one, "How are the Psi-Upsilon boys? Oh, they're all right!"

A passer-by, puzzled at the scene, made his way into the store and soon
solved the mystery. In a large cage in the center was an enormous green
and yellow parrot, which was hanging by one foot to a swinging perch, and
trolling forth in different voices with the ease of an accomplished
ventriloquist. He resumed a normal position as he was approached, and
flapping his wings bellowed out, "Hurrah for Elaine and Logan!" Then,
cocking his head on one side, he dropped into a more conversational tone,
and with a regular "Alice in Wonderland" air remarked: "It's never too
late to mend a bird in the hand;" and again, after a pause, "It's a long
lane that never won fair lady." His visitor affably remarked:

"You're quite an accomplished bird, Polly," and quick as a flash the
creature replied:

"I can spell, I can. C-a-t, cat. D-o-g, fox," with an affectation of
juvenility which was grewsome. He resented an ill-advised attempt at
familiarity by snapping at the finger which tried to scratch his poll,
and barked out:

"Take care! I'm a bad bird, I am. You betcher life!"

"He's one of the cleverest parrots I have had for some time," said his
owner, Mr. Holden. "In fact, he is almost as good as Ben Butler, whom I
sold to Patti. His stock of proverbs seems inexhaustible, and he makes
them quite funny by the ingenious way in which he mixes them up. I could
not begin to tell you all the things he says, but his greatest
accomplishment is his singing. He is a double yellowhead - the only
species of parrot which does sing. The African grays are better talkers,
but they do not sing. They only whistle. What do I ask for him? Oh, I
think $200 is cheap for such a paragon, don't you?" - _N.Y. Tribune._

* * * * *




THE ROSCOFF ZOOLOGICAL LABORATORY.


The celebrated Roscoff zoological station was founded in 1872, and has
therefore been in existence for thirteen years; but it may be said that
it has changed appearance thirteen times. Those who, for the last six or
seven years, have gone thither to work with diligence find at every
recurring season some improvement or new progress.

A rented house, a small shed in a yard, little or no apparatus, and four
work rooms - such was the debut of the station; and modest it was, as may
be seen. Later on, the introduction of a temporary aquarium, which,
without being ornamental, was not lacking in convenience, sufficed for
making some fine discoveries regarding numerous animals.

A small boat served for supplying necessaries to the few workers who were
then visiting Roscoff; but as the number of these kept gradually
increasing, it became necessary to think of enlarging the station, and
the purchase of a piece of property was decided upon. Since then, Mr.
Lacaze Duthiers has done nothing but develop and transform this first
acquisition. A large house, which was fitted up in 1879, formed the new
laboratory. This was built in a large garden situated nearly at the edge
of the sea. We say _nearly_, as the garden in fact was separated from the
sea by a small road. The plan in Fig. 1 shows that this road makes an
angle; but formerly it was straight, and passed over the terrace which
now borders upon the fish pond. How many measures, voyages, and endless
discussions, and how much paper and ink, it has taken to get this road
ceded to the laboratory! Finally, after months of contest, victory
rewarded Mr. Duthiers's tenacity, and he was then able to begin the
construction of a pond and aquarium. All this was not done at once.

[Illustration: FIG. 1. - PLAN OF THE ROSCOFF LABORATORY.]

Another capital improvement was made in 1882. The public school adjoining
the establishment was ceded to it, the separating walls fell, the school
became a laboratory, the class rooms were replaced by halls for research,
and now no trace of the former separation can be seen - so uniform a whole
does the laboratory form. No one knows what patience it required to form,
piecemeal as it were, so vast an establishment, and one whose every part
so completely harmonizes.

During the same year a park, one acre in area, was laid out on the beach
opposite the laboratory. This is daily covered by the sea, and forms a
preserve in which animals multiply, and which, during the inclement
season, when distant excursions are impossible, permits of satisfying the
demands that come from every quarter. All, however, is not finished. Last
year a small piece of land was purchased for the installation of
hydraulic apparatus for filling the aquarium. This acquisition was
likewise indispensable, in order to prevent buildings from being erected
upon the land and shutting off the light from the work rooms opposite.
Alas, here we find our enemy again - the little road! Negotiations have
been going on for eighteen months with the common council, and, what is
worse, with the army engineers, concerning the cession of this wretched
footpath.

The reader now knows the principal phases of the increases and
improvements through which the Roscoff station has passed. If, with the
plan before his eyes, he will follow us, we will together visit the
various parts of the laboratory. The principal entrance is situated upon
the city square, one of the sides of which is formed by the buildings of
the station. We first enter a large and beautiful garden ornamented with
large trees and magnificent flowers which the mild and damp climate of
Roscoff makes bloom in profusion. We next enter a work room which is
designed for those pupils who, doing no special work, come to Roscoff in
order to study from nature what has been taught them theoretically in the
lecture courses of schools, etc. There is room here for nine pupils, to
each of whom the laboratory offers two tables, with tanks, bowls,
reagents, microscopes, and instruments of all kinds for cabinet study, as
well as for researches upon animals on the beach. Here the pupils are in
presence of each other, and so the explanations given by the laboratory
assistants are taken advantage of by all. At the end of this room, on
turning to the left, we find two large apartments - the library and
museum. Here have been gradually collected together the principal works
concerning the fauna of Roscoff and the English Channel, maps and plans
useful for consultation, numerous memoirs, and a small literary library.
The scientific collection contains the greater portion of the animals
that inhabit the vicinity of Roscoff. To every specimen is affixed a
label giving a host of data concerning the habits, method of capture, and
the various biological conditions special to it. In a few years, when the
data thus accumulated every season by naturalists have been brought
together, we shall have a most valuable collection of facts concerning
the fauna of the coast of France. Two store rooms at the end of these
apartments occupy the center of the laboratory, and are thus more easy of
access from the work rooms, and the objects that each one desires can be
quickly got for him.

[Illustration: FIG. 2. - INTERIOR OF ONE OF THE STALLS FOR STUDY.]

After the store rooms comes what was formerly the class room for boys,
and which has space for three workers, and then the former girls' class
room, which has space for eight more. Let us stop for a moment in this
large room, which is divided up into eight stalls, each of which is put
at the disposal of some naturalist who is making original researches.
Fig. 2 represents one of these, and all the rest are like it. Three
tables are provided, the space between which is occupied by the worker.
Of these, one is reserved for the tanks that contain the animals,
another, placed opposite a window giving a good light, supports the
optical apparatus, and the last is occupied by delicate objects,
drawings, notes, etc., and is, after a manner, the worker's desk. Some
shelving, some pegs, and a small cupboard complete the stall. It is
unnecessary to say that the laboratory furnishes gratuitously to those
who are making researches everything that can be of service to them.

Four of these stalls are situated to the north, with a view of the sea,
and the other four overlook the garden. They are separated from each
other by a simple partition, and all open on a wide central corridor that
leads to the aquarium. Before reaching the latter we find two offices
that face each other, one of them for the lecturer and the other for the
preparator. These rooms, as far as their arrangement is concerned, are
identical with the stalls of the workers. The laboratory, then, is
capable of receiving twenty-three workers at a time, and of offering them
every facility for researches.

[Illustration: FIG. 3. - GENERAL VIEW OF THE ROSCOFF LABORATORY.]

The aquarium is an immense room, 98 ft. in length by 33 in width, glazed
at the two sides. It is at present occupied only by temporary tanks that
are to be replaced before long by twenty large ones of 130 gallons
capacity, and two oval basins of from 650 to 875 gallons capacity,
constructed after the model of the one that is giving so good results at
Banyuls. At the extremity of the aquarium there is a store room
containing trawls, nets of all kinds, and mops, for the capture of
animals. Here too is kept the rigging of the two laboratory boats, the
Dentale and Laura. Above the store room is located the director's work
room.

A wide terrace separates the aquarium from the pond. This latter is 38
yards long by 35 wide. Thanks to a system of sluice valves, it is filled
during high tide, and the water is shut in at low tide, thus permitting
of having a supply of living animals in boxes and baskets until the
resources of the laboratory permit of a more improved arrangement. This
basin is shown in Fig. 3. It is at the north side of the laboratory as
seen from the beach. Here too we see the aquarium, the garden, and a
portion of the shore that serves as a post for the station boats.

We must not, in passing, fail to mention the extreme convenience that the
proximity of the aquarium work room to the pond and sea offers to the
student.

This entire collection of halls, constituting the scientific portion of
the laboratory, occupies the ground floor. The first and second stories
are occupied by sleeping apartments, fourteen in number. These, without
being luxurious, are sufficiently comfortable, and offer the great
advantage that they are very near the work rooms, thus permitting of
observing, at leisure, and at any hour of the day or night, the animals
under study.

Everything is absolutely free at the laboratory. The work rooms,
instruments, reagents, boats, dwelling apartments, etc., are put at the
disposal of all with an equal liberality; and this absence of distinction
between rich or poor, Frenchmen or foreigners, is the source of a
charming cordiality and good will among the workers.

Shall we speak, too, of the richness of the Roscoff fauna? This has
become proverbial among zoologists, as can be attested by the 265 of them
who have worked at the laboratory. The very numerous and remarkable
memoirs that have been prepared here are to be found recorded in the
fourteen volumes of the _Archives de Zoologie Experimentale_ founded by


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Online LibraryVariousScientific American Supplement, No. 520, December 19, 1885 → online text (page 7 of 9)