Scientific American Supplement, No. 401, September 8, 1883

V >> Various >> Scientific American Supplement, No. 401, September 8, 1883

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SEMI-DETACHED VILLAS, BROMFIELD CRESCENT, HEADINGLEY.

These houses are situated in a pleasant part of Headingley, which is
the favorite residential suburb in the locality of Leeds. As regards
accommodation, the ground-floor of each house comprises good-sized
drawing and dining rooms, each with bay windows; well-lighted entrance
halls, opening upon wooden verandas; kitchen, pantry, and scullery; on
first floor are three good bedrooms, a bathroom, and other necessary
accommodation; on second floor are two additional bedrooms. The basement
contains coal-place and larder.

In these houses an attempt has been made to produce conveniently-planned
and well-arranged habitations, combined with a pleasing and picturesque
exterior, without involving a large outlay of money. The materials used
are brick of a deep red color for facings, red terra-cotta from Messrs.
Wilcock & Co., of Burmantofts, for moulded strings, sills, etc., and a
very sparing use of stone from the Harehills Quarries. The front gables
are constructed of timber in solid scantlings, well framed, and pinned
together with oak pegs, filled in and well backed behind with brickwork;
the panels faced with cement, which, together with the cored cornice,
are finished in vellum color. The whole of the woodwork of exterior is
painted a neutral shade of peacock blue, forming an admirable contrast
with the deep red of the bricks, the sashes and casements only being
finished in cream color. The whole of the chimneypieces in the interior
are carried out from the architect's special design; those in the
drawing-rooms being of mahogany, finished in rosewood color, and those
in dining-rooms of oak, stained with ammonia and dull wax polished.

[Illustration: SUGGESTIONS IN ARCHITECTURE.--SEMI-DETACHED VILLAS,
BROMFIELD CRESCENT, HEADINGLEY, LEEDS.]

The houses, with outbuildings and boundary walls, which have been
erected for Mr. John Hall Thorp, of Bromfield, Headingley, have cost
L1,450, or thereabouts, this amount not including the price of
land. They have been carried out from the designs and under the
superintendence of Mr. William H. Thorp, A.R.I.B.A., architect, of St.
Andrew's Chambers, Park Row, Leeds.--_The Architect_.

* * * * *

THE DWELLINGS OF THE POOR IN PARIS.

In view of the possible approach of cholera, and the sanitary
precautions that even the most neglectful of authorities are constrained
to take, it is of some interest to us, says the _Building News_, to know
how the poor are housed in the city of Paris, which contains, more than
any city in the world, the opposite poles of luxurious magnificence
and of sordid, bestial poverty. The statistics of the Parisian working
classes in the way of lodgings are not of an encouraging nature, and
reflect great discredit on the powers that be, who can be stern enough
in the case of any political question, but are blind to the spectacle
of fellow creatures living the life of beasts under their very eyes. In
1880, the Prefect of Police gave licenses to 21,219 arrivals in the city
of French origin, and to 7,344 foreigners. In the succeeding year,
the former had increased to 22,061, while the latter had somewhat
diminished, being only 5,493. There was a census taken in 1881, from
which it appeared that Paris contained 677,253 operatives and 255,604
employes and clerks, while out of every 1,000 inhabitants, 322 only
were born in the city, and 565 came from the departments or the French
colonies. The foreign element in the working classes has increased
very rapidly, numbering 119,349 in 1876, to which by 1881 there was an
addition of 44,689. To every 1,000 inhabitants, Paris now numbers 75
foreigners, though in 1876 the proportion was only 60. It may not be
amiss to state that the annual increase of the Paris population is at
the rate of 56,043 persons, and that in the five years 1876-81, the city
received 280,217 additional mouths. The total population of the capital
is 2,239,928, of whom 1,113,326 are males.

Returning to the poorer classes, we find that in 1872 they were
estimated at 100,000; but that in 1873 they had risen to 113,733, and
in 1880 to 123,735. It is unfortunate to be obliged to say that the
majority of these people are housed worse in Paris than in almost any
other great city in the world. There are two classes of lodgings for the
poor--the one where the workman rents one or more rooms for his family,
and, perhaps, owns a little furniture; the other, a single room tenanted
for the night only by the unmarried man who pays for his bed in the
morning and gets his meals anywhere that he can. Readers will remember
how, under the auspices of M. Haussmann, western Paris was almost pulled
down and transformed into a series of palatial boulevards and avenues.
While the work lasted the Paris workman was well pleased; but he did
not like it quite so much when the demon of restoration and renovation
invaded his own quarters, such as the Butte des Moulins, and all that
densely populated district through which the splendid Avenue de l'Opera
now runs. The effect of all this was to drive the workman into the
already crowded quarters at the barriers, such as La Gare, St. Lambert,
Javel, and Charonne, where, according to the last statistics of the
_Annuaire_, the increase was at the rate of 415 per 1,000. Of course the
ill health that always pervaded these quarters increased also; and, from
the reports of Dr. Brouardel and M. Muller, the number of deaths from
typhoid and diphtheria were doubled in ten years. Dr. Du Mesnil, in
making his returns for 1881 of convalescents from typhoid, remarked that
the most unsanitary arrondissements were the 4th, 11th, 15th, 18th, and
19th--precisely those to which the principal migrations of laborers had
taken place. The 18th arrondissement, which in 1876 had only 601 lodging
houses with 8,933 lodgers, had, in 1882, over 850, with 20,816 inmates.
In the 19th arrondissement there were 517 houses in 1876, with 9,074
lodgers, and 752 in 1882, with 17,662 inhabitants.

It is not only the crowded condition of the poor quarters that is such a
standing menace to the health of the city, but also the shocking state
of the rooms, which the unhappy lodgers are obliged to put up with. The
owners of the property are, as happens in other places besides Paris,
unscrupulous and grasping to the last degree, and have not only divided
and subdivided the accommodation wherever possible, but have even raised
the rental in nearly all cases. Whole families are crowded into a small
apartment, icy cold in winter, an oven in summer, the only air and
daylight which reaches the interior coming from a window which looks on
to a dirty staircase or a still fouler court reeking with sewage. There
are at the present time in Paris 3,000 lodgings which have neither stove
nor chimney; over 5,000 lighted only by a skylight; while in 4,282 rooms
there are four children in each below 14 years of age; 7,199 with three
children; and 1,049 with four beds in each. The Parisian population has
augmented only 15 per cent. in seven years; but the district of poor
lodging houses has increased by twenty per cent., and the number of
lodgings by about 80 per cent. It is true that a law was passed in 1850
to provide for the sanitary supervision of this class of property; but
in Paris the law is a dead letter, and, although it is now active in the
provinces and in places like Marseilles, Lyons, Bordeaux, and Nantes, it
is applied, even there, in a jerky and intermittent manner.

Perhaps the worst of the abominable dogkennels called houses was the
group known as the Cite des Kroumirs, in the 13th arrondissement, which,
by a strange irony, was built on land belonging to the Department of
Public Assistance, which was let out by that body to a rich tenant, who
sublet it to these lodging-house owners. This veritable den of infection
and misery has now been demolished; but there are plenty of others quite
as bad. Notably, there is the Cite Jeanne d'Arc (a poor compliment to
have named it after that sturdy heroine), an enormous barrack of five
stories, which contains 1,200 lodgings and 2,486 lodgers. No wonder that
it was decimated in 1879 by smallpox, which committed terrible ravages
here. The Cite Dore is grimly known by the poor-law doctors as the
"Cemetery Gateway." The Cite Gard, in the Rue de Meaux, is inhabited
by 1,700 lodgers, although it is almost in ruins. The Cite Philippe is
tenanted by 70 chiffonniers, and anybody who knows what are the contents
of the chiffonnier's basket, or _hotte_, may easily guess at the
effluvia of that particular group of houses. A large lodging-house in
the Rue des Boulangers is tenanted by 210 Italians, who get their living
as models or itinerant musicians. Both house and tenants are declared to
be unapproachable from the vermin.

It is some satisfaction to know that these houses have lately awakened
the apathy of some of the public bodies, and that more than one
scheme is being put forward with a view of erecting proper industrial
dwellings. The Municipal Council is negotiating with the Credit Foncier
for the erection of a certain number of cheap houses, which, for the
space of twenty years, will be exempt from all taxes, such as
octroi, highway, door and window tax, etc. There are also one or
two semi-private companies, which are occupying themselves with the
question, and it is to be hoped that the rumors of the pestilence in
Egypt may hasten the much-needed reform.

* * * * *

There can be no doubt, says the _Engineer_, that the inventor who could
supply in a really portable form a machine or apparatus that could give
out two or three horse power for a day would reap an enormous fortune.
Up to the present time, however, nothing of the kind has been placed
in the market. Gas is laid on to most houses now, and gas engines are
plenty enough, yet they do not meet the want which a storage battery may
be made yet perhaps to supply.

* * * * *

RECENT EXPERIMENTS AFFECTING THE RECEIVED THEORY OF MUSIC.

To prove the incorrectness of Helmholtz's statement that beats do not
colesce into musical sounds, but that the ear will distinguish them as a
rumbling noise, even when their number rises as high as 132 vibrations
per second, Rudolph Koenig has constructed a series of tuning forks,
recently presented by President Morton to the Stevens Institute of
Technology. The following table exhibits the number of vibrations per
second of these forks, the ratios of their vibrations when two are
sounded together, the number of beats produced, and the resultant sound:

Vibrations per second. Ratio. Beats. Sounds.

3840 :4096 15:16 128 Ut_{2}
3904 : " 61:64 96 Sol_{1}
3936 : " 123:128 80 Mi_{1}
3968 : " 31:32 64 Ut_{1}
3976 : " 497:512 60 Si_{-1}
3989.3 : " 187:192 53.3 La_{-1}
4000 : " 125:128 48 Sol_{1}
4010.7 : " 47:48 42.7 Fa_{-1}
4016 : " 251:256 40 Mi_{-1}
4024 : " 503:512 36 Re_{-1}
7936 : 8192 31:32 128 Ut_{2}
8064 : " 63:64 64 Ut_{1}
8096 : " 253:256 48 Sol_{-1}
8106.7 : " 95:96 42.7 Fa_{-1}
8112 : " 507:512 40 Mi_{-1}
8120 : " 1015:1024 36 Re_{-4}
8128 : " 127:128 32 Ut_{-4}

On sounding two forks nearly in unison, the sound heard corresponds to
a number of vibrations equal to the difference of the numbers of
vibrations of the forks.

On sounding two forks, one of which is nearly the octave of the other,
the ear perceives a sound, which is that given by vibrations whose
number equals the difference in the number of vibrations of the higher
fork and the upper octave of the lower fork.

Koenig has also found out the laws of the resultant sounds produced
by other intervals than the octave, and has extended his researces to
intervals differing by any number of vibrations, as may be seen from the
above table.

His conclusion is that beats and resultant sounds are one and the same
phenomenon.

Thus, for example, the lowest number of vibrations capable of producing
a musical sound is 32 per second; in like manner, a clear musical sound
is produced by two simple notes of sufficient intensity which produce 32
beats per second.

Koenig also made a very ingenious modification of the siren for the
purpose of enabling Seebeck to sound simultaneously notes whose
vibrations had any given ratio. It is furnished for this purpose with
eight disks, each of which contains a given number of circles of
holes arranged at different angular distances. A description of this
instrument, which is also the property of the Stevens Institute, and of
Seebeck's experiments is thus given in a letter by Koenig himself.

I.

_Effects produced when the isochronism of the shocks is not perfect_.

A.

In order to produce a note, the succession of shocks must not deviate
much from isochronism.

If the isochronism is but little impaired, we obtain a note
corresponding to the mean interval of the shocks.

If the intervals between the shocks are alternately t and t', and if the
difference between t and t' is slight, we obtain the two notes t+t' and
(t+t')/2. If the intervals between the shocks are alternately t, t', and
t'', we obtain the two notes t+t'+t'' and (t+t'+t")/3.

Disk No. 1 has--

On circle No. 1 12 holes, angular distances t=30 deg.
" " 2 24 " " " 15 deg.
" " 3 36 " " " 10 deg.
" " 4 36 " at irregular distances.
" " 5 36 " distances t= 101/2 deg., t'=l0 deg.,t''=91/2 deg.
" " 6 36 " " 11 deg. 10 deg. 9 deg.
" " 7 36 " " 16 deg. 14 deg.
" " 8 36 " " 161/2 deg. 131/2 deg.

Circle No. 8 produces the two notes of circles 1 and 2; circle No. 7 the
same, but the low note is stronger than in 8.

Circle 6 produces the notes of circles 1 and 3, and so does circle 5,
but in the latter the low note is stronger than in 6.

Circle 4 produces a noise approximating only to the note of circle 3.

By pulling out one of the buttons of the wind chest, we admit the air
through eleven holes at a time, having an angular distance of 30 deg. and
directing it against the corresponding circle of holes on the turning
disk. If the arrangement of holes is not repeated identically twelve
times on the same circle, we cannot, of course, make use of the above
arrangements of holes of the wind tube, and we must then employ one of
the movable brass tubes, which communicate with the interior of the wind
chest by means of rubber tubes and stopcocks. The experiment with disk
1, circle 4, for example, requires the use of one of these two tubes,
while the perforated wind tube of the wind chest may be used with all
the other circles of the same disk.

B.

If t is much less than t', while t' is a multiple of t, the note
(t+t')/2 disappears, and the notes t+t' and t are heard.

Disk No. 2 has--

On circle No. 1 12 holes, distances 30 deg.
" " 2 36 " " 10 deg.
" " 3 48 " " 71/2 deg.
" " 4 60 " " 6 deg.
" " 5 24 " " t= 5 deg., t'=25 deg.
" " 6 24 " 6 deg. 24 deg.
" " 7 24 " 71/2 deg. 221/2 deg.
" " 8 24 " 10 deg. 20 deg.

Circle 8 produces the notes of circles 1 and 2; circle 7, those of 1 and
3; circle 6, those of 1 and 4; and circle 5, the note of circle 1 and of
its sixth harmonic.

C.

If the same circular arc is divided into m and n equal parts; that is to
say, if mt=nt', we obtain the notes m and n.

Disk No. 3 has--

Distances.
On circle No. 1 24 holes, distances 15 deg.
" " 2 24 " " 15 deg. & 27 holes, 13-1/3 deg.
" " 3 24 " " 15 deg. " 30 " 12 deg.
" " 4 24 " " 15 deg. " 32 " 11-1/4 deg.
" " 5 24 " " 15 deg. " 36 " 10 deg.
" " 6 24 " " 15 deg. " 40 " 9 deg.
" " 7 24 " " 15 deg. " 45 " 8 deg.
" " 8 24 " " 15 deg. " 30, 36, & 48 holes

Circle 1 produces a single note, circle 2 a second, circle 3 a third,
circle 4 a fourth, 5 a fifth, 6 a sixth, 7 a seventh, and 8 a perfect
chord.

II.

_Experiments to prove that the shocks may proceed from two or several
different places to conspire in the formation of a note, provided that
the isochronism of the shocks is sufficiently exact, and that the shocks
are produced in the same direction_.

Disk No. 4 has--

On circle 1 24 holes.
" " 2 36 "
" " 3 23 "
" " 4 12 at an angular distance of 10 deg. from the holes
of circle 3.
" " 5 12 holes at an ang. dist. of 20 deg. from those of circle 3
" " 6 12 " " " 0 deg. "
" " 7 12 " " " 15 deg. "
" " 8 12 " " " 15 deg. "

1. If from the same side two currents of air at an angular distance of
15 deg. are directed against circle No. 8 of 12 holes, we obtain the octave
of the note produced by the same circle if only one current is used.

The wind-chest is provided with a special arrangement for this
experiment. By pulling out button 8, we give vent to 12 currents of air
spaced like the twelve holes of the disk; on pulling out button 9 we
also produce 12 currents, but they are situated just between the first.
Each of these two buttons pulled out alone will produce the same note
corresponding to 12 holes, but drawn together they produce the octave,
or the note of circle 1.

2. If two currents of air are directed against two similar circles whose
holes are situated on the same radii, we obtain the same result.

In this experiment, circles 7 and 8 are sounded by pulling out buttons 7
and 9.

3. When two currents of air are directed on the same radius against two
circles of similar holes arranged alternately, these circles sounded
simultaneously will produce the octave of the note which one of them
would give alone.

This experiment is performed by sounding circles 6 and 7 and pulling out
buttons 6 and 7.

4. If we direct three currents of air on the same radius against three
similar circles having holes alternating by a third of the distance
between two holes of the same circle, the three circles together produce
the fifth of the octave (Note 3) of a single circle.

Circles 3, 4, and 5 sounded together emit the note of circle 2.

(By sounding only two circles, 3 and 4, or 4 and 5, we make the same
experiment with two circles as disk No. 2 enabled us to make with
circle 8 alone; also, by sounding circle 3 alone, we obtain the note
corresponding to 12 holes; then pulling out button 4, the notes
corresponding to 12 and 36 holes are heard suddenly and very strongly;
but as soon as circle 5 is sounded also, the note of 12 disappears
completely, and we have left only that corresponding to 36 holes.)

III.

_Effects of interference produced by shocks in opposite directions_.

1. If we direct against a circle of holes two currents of air in
opposite directions, the note obtained with a single current is very
much weakened, if the two currents reach the holes simultaneously.
If the impulses are not isochronous, the intensity of the note is
increased.

2. If the two currents are directed against two circles of the same
number of holes, the effect is the same as for the two preceding cases.

3. If two currents of air are directed against two circles, one of which
has twice as many holes as the other, we obtain only the low note if
every shock of one is isochronous with every shock of the other.

We obtain the notes of both circles, one of which is the octave of the
other, if there is no isochronism between the shocks.

Disk No. 5 has three circles of 36, 36, and 72 holes. The air currents
are directed against the circles of holes through the movable tubes,
made so that they can be detached at pleasure. All these experiments
require great precision in the arrangement of these wind tubes. To make
sure that the tubes are simultaneously before two holes of the disk, it
is well to put little rods through the holes, reaching into the wind
tubes, and to remove them only when the tubes are firmly attached. The
experimenter should be careful also to place the two tubes exactly
at the same distance from the turning disk. It is clear that
notwithstanding all these precautions we never obtain perfect
interference, but only the weakening of notes that ought to disappear
entirely if all the arrangements were made with mathematical exactness,
and also if the ear could have absolutely the same position with regard
to impulses produced in opposite directions.

IV.

_Beats_.

Disk No. 6 has--

8 circles of holes to the number of 1, 2, 23, 24, 25, 47, 48, 49.

Circles 3 and 4, 4 and 5, 6 and 7, and 7 and 8 ought to produce as many
beats as circle 1 produces simple shocks; and circles 3 and 5, 6 and 8,
as many beats as circle 2 produces simple shocks; but we must content
ourselves in these experiments with a much less perfect result, for the
following reasons: The disk never being rigorously plane, alternately
approaches the single wind pipe and recedes from it. No matter how
slight this deviation is, every sound given by a single circle is heard
with periodical intensities which complicate the phenomenon. This
inconvenience could be avoided by placing several wind-pipes around the
circle; but while we can extend the period of the holes in two circles
(whose difference is 1) around the whole circle by blowing through a
single wind tube, we would be compelled to limit it to the distance
between two wind tubes, and it would become too short; for, when the
disk rotates with a velocity sufficient to produce notes high enough and
intense enough, the beats become too numerous to be easily perceived.

Besides these provisions, which sufficiently illustrate the points to
which we desire to call especial attention, Koenig also furnishes two
more disks.

The seventh contains 8 circles having 48, 54, 60, 64, 72, 80, 90, and
96 holes respectively. The 1st, 3d, 5th, and 8th will produce a perfect
chord when the air is admitted through the 11 holes in the wind chest;
with one wind tube the entire gamut may be obtained.

Finally the eighth disk contains 8 circles of holes, whose numbers are
in the ratio of 1:2:3:4, etc., and which may be used to illustrate
harmonics. C. F. K.

* * * * *

THE MOTIONS OF CAMPHOR UPON THE SURFACE OF WATER.

[Footnote: Continued from SUPPLEMENT No. 391, page 6240.]

To have these movements occur in a constant and invariable manner upon
the surface of water, and especially upon mercury, it is necessary to
take precautions in regard to cleanliness, this being something that
we have purposely neglected to mention to our readers. For we wished,
through this voluntary omission, to stimulate their sagacity by bringing
them face to face with difficulties that they will perhaps have
succeeded in overcoming, with causes of error that they will have
perceived, and the principal one of which is the want of absolute
cleanliness in the water, vessels, and instruments that they may have
used for the experiments.

Thus, very probably, they will have more than once seen the camphor
remain immovable when placed in vessels in which they had hoped to
be able to see it undergo its gyratory and other motions. Their
astonishment will have been no less than our own was when we noticed
the sudden cessation of the camphor's motions under the influence of
vitreous or metallic objects, such as glass rods or tubes, pieces of
gold, silver, or copper coin, table knives, etc., dipped into the liquid
in which such motions were taking place before the immersion of the
objects under consideration.

The instantaneously _sedative_ power of the human fingers, or of a hair,
will have, perhaps, reminded them of some sort of sorcery, or of some
diabolic art worthy of the great Albert.

[Illustration: APPARATUS FOR THE STUDY OF THE MOTIONS OF CAMPHOR.]

As for ourself, we confess that, after repeating the curious experiments
of Mr. Dutrochet day after day, and scrupulously following his
directions, we have, in the presence of our results, that were exactly
identical with his, almost been tempted to believe ourself to be the
victim of some occult power, or at least of some optical illusion,
the true cause of which remained a mystery to us. Finally, after
many fruitless attempts to find a key to the enigma that engaged our
attention, the light finally dawned upon us, and then shone straight in
our eyes.

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