Scientific American Supplement, No. 460, October 25, 1884 by Various
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Various >> Scientific American Supplement, No. 460, October 25, 1884
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[Illustration: FIG. 2]
But as the line in question was laid with all the curves unnecessarily
quick, even those in the "pass-bies," I thought it expedient to employ
differential gear, as illustrated at D, Fig. 1, which is a sketch plan
showing the mechanism employed. M is a Siemens electric motor running at
650 revolutions per minute; E is a combination of box gearing, frictional
clutch, and chain pinion, and from this pinion a steel chain passes around
the chain-wheel, H, which is free to revolve upon the axle, and carries
within it the differential pinion, gearing with the bevel-wheel, B squared, keyed
upon the sleeve of the loose tram-wheel, T squared, and with the bevel-wheel, B,
keyed upon the axle, to which the other tram-wheel, T, is attached. To the
other tram-wheels no gear is connected; one of them is fast to the axle,
and the other runs loose, but to them the brake is applied in the usual
manner.
The electric current from the collector passes, by means of a copper wire,
and a switch upon the dashboard of the car, and resistance coils placed
under the seats, to the motor, and from the motor by means of an adjustable
clip (illustrated in diagram, Fig. 2) to the axles, and by them through the
four wheels to the rails, which form the return circuit.
[Illustration: FIG. 3]
I have designed many modifications of the track, but it is, perhaps, best
at present to describe only that which I have in actual use, and it is
illustrated in diagram, Fig. 3, which is a sectional and perspective view
of the central channel. L is the surface of the road, and SS are the
sleepers, CC are the chairs which hold the angle iron, AA forming the
longitudinally slotted center rail and the electric lead, which consists of
two half-tubes of copper insulated from the chairs by the blocks, I, I. A
special brass clamp, free to slide upon the tube, is employed for this
purpose, and the same form of clamp serves to join the two ends of the
copper tubes together and to make electric contact. Two half-tubes instead
of one slotted tube have been employed, in order to leave a free passage
for dirt or wet to fall through the slot in the center rail to the drain
space, G. Between chair and chair hewn granite or artificial stone is
employed, formed, as shown in the drawing, to complete the surface of the
road and to form a continuous channel or drain. In order that this drain
may not become choked, at suitable intervals, in the length of the track,
sump holes are formed as illustrated in diagram, Fig. 4 These sump holes
have a well for the accumulation of mud, and are also connected with the
main street drain, so that water can freely pass away. The hand holes
afford facility for easily removing the dirt.
In a complete track these hand holes would occasionally be wider than shown
here, for the purpose of removing or fixing the collector, Fig. 5, which
consists of two sets of spirally fluted rollers free to revolve upon
spindles, which are held by knuckle-joints drawn together by spiral
springs; by this means the pressure of the rollers against the inside of
the tube is constantly maintained, and should any obstruction occur in the
tube the spiral flute causes it to revolve, thus automatically cleansing
the tubes.
[Illustration: FIG. 4]
The collector is provided with two steel plates, which pass through the
slit in the center rail; the lower ends of these plates are clamped by the
upper frame of the collector, insulating material being interposed, and the
upper ends are held in two iron cheeks. Between these steel plates
insulated copper strips are held, electrically connected with the collector
and with the adjustable clip mounted upon the iron cheeks; this clip holds
the terminal on the end of the wire (leading to the motor) firmly enough
for use, the cheeks being also provided with studs for the attachment of
leather straps hooked on to the framework of the car, one for the forward
and one for backward movement of the collector. These straps are strong
enough for the ordinary haulage of the collector, and for the removal of
pebbles and dirt that may get into the slit; but should any absolute block
occur then they break and the terminal is withdrawn from the clip; the
electric contact being thereby broken the car stops, the obstruction can
then be removed and the collector reconnected without damage and with
little delay.
[Illustration: FIG. 5]
In order to secure continuity of the center rail throughout the length of
the track, and still provide for the removal of the collector at frequent
intervals, the framework of the collector is so made that, by slackening
the side-bolts, the steel plates can be drawn upward and the collector
itself withdrawn sideways through the hand holes, one of the half-tubes
being removed for the purpose.
Fig. 6 illustrates another arrangement that I have constructed, both of
collector and method of collecting.
[Illustration: FIG. 6]
As before mentioned, the arrangement now described has been carried out in
a field near the works of Messrs. Smith, Baker & Co., Cornbrook Telegraph
Works, Manchester, and its working efficiency has been most satisfactory.
After a week of rain and during drenching showers the car ran with the same
speed and under the same control as when the ground was dry.
This I account for by the theory that when the rails are wet and the tubes
moist the better contact made compensates for the slight leakage that may
occur.
At the commencement of my paper I promised to confine myself to work done;
I therefore abstain from describing various modifications of detail for the
same purpose. But one method of supporting and insulating the conductor in
the channel may be suggested by an illustration of the plan I adopted for a
little pleasure line in the Winter Gardens, Blackpool.
[Illustration: FIG. 7.]
Fig. 7. There the track being exclusively for the electric railway, it was
not necessary to provide a center channel; the conductor has therefore been
placed in the center of the track, and consists of bar iron 11/4 in. by 1/2
in., and is held vertically by means of studs riveted into the side; these
studs pass through porcelain insulators, and by means of wooden clamps and
wedges are held in the iron chairs which rest upon the sleepers. The iron
conductors were placed vertically to facilitate bending round the sharp
curves which were unavoidable on this line.
The collector consists of two metal slippers held together by springs,
attached to the car by straps and electrically connected to the motor by
clips in the same manner as the one employed in Manchester.
I am glad to say that, notwithstanding the curves with a radius of 55 feet
and gradients of 1 in 57, this line is also a practical success.
* * * * *
FIRES IN LONDON AND NEW YORK.
When the chief of the London Fire Brigade visited the United States in
1882, he was, as is the general rule on the other side of the Atlantic,
"interviewed"--a custom, it may be remarked, which appears to be gaining
ground also in this country. The inferences drawn from these interviews
seem to be that the absence of large fires in London was chiefly due to the
superiority of our fire brigade, and that the greater frequency of
conflagrations in American cities, and particularly in New York, was due to
the inferiority of their fire departments. How unjust such a comparison
would be is shown in a paper presented by Mr. Edward B. Dorsey, a member
of the American Society of Civil Engineers, to that association, in which
the author discusses the comparative liability to and danger from
conflagrations in London and in American cities. He found from an
investigation which he conducted with much care during a visit to London
that it is undoubtedly true that large fires are much less frequent in the
metropolis than in American cities; but it is equally true that the
circumstances existing in London and New York are quite different. As it is
a well-known fact that the promptness, efficiency, and bravery of American
firemen cannot be surpassed, we gladly give prominence to the result of the
author's investigations into the true causes of the great liability of
American cities to large fires. In a highly interesting comparison the
writer has selected New York and London as typical cities, although his
observations will apply to most American and English towns, if, perhaps,
with not quite the same force. In the first place, the efforts of the
London Fire Brigade receive much aid from our peculiarly damp climate. From
the average of eleven years (1871-1881) of the meteorological observations
made at the Greenwich Observatory, it appears that in London it rains, on
the average, more than three days in the week, that the sun shines only
one-fourth of the time he is above the horizon, and that the atmosphere
only lacks 18 per cent. of complete saturation, and is cloudy seven-tenths
of the time. Moreover, the humidity of the atmosphere in London is very
uniform, varying but little in the different months. Under these
circumstances, wood will not be ignited very easily by sparks or by contact
with a weak flame. This is very different from the condition of wood in the
long, hot, dry seasons of the American continent. The average temperature
for the three winter months in London is 38.24 degrees Fahr.; in New York
it is 31.56 degrees, or 6.68 degrees lower. This lower range of temperature
must be the cause of many conflagrations, for, to make up for the
deficiency in the natural temperature, there must be in New York many more
and larger domestic fires. The following statistics, taken from the records
of the New York Fire Department, show this. In the three winter months of
1881, January, February, and December, there were 522 fire alarms in New
York, or an average per month of 174; in the remaining nine months 1,263,
or an average per month of 140. In the corresponding three winter months of
1882 there were 602 fire alarms, or an average per month of 201; in the
remaining nine months 1,401, or an average per month of 155. In round
numbers there were in 1881 one-fourth, and in 1882 one-third more fire
alarms in the three winter months than in the nine warmer months. We are
not aware that similar statistics have ever been compiled for London, and
are consequently unable to draw comparison; but, speaking from
recollection, fires appear to be more frequent also in London during the
winter months.
Another cause of the greater frequency of fires in New York and their more
destructive nature is the greater density of population in that city. The
London Metropolitan Police District covers 690 square miles, extending 12
to 15 miles in every direction from Charing Cross, and contained in 1881 a
population of 4,764,312; but what is generally known as London covers 122
square miles, containing, in 1881, 528,794 houses, and a population of
3,814,574, averaging 7.21 persons per house, 49 per acre, and 31,267 per
square mile. Now let us look at New York. South of Fortieth Street between
the Hudson and East Rivers, New York has an area of 3,905 acres, a fraction
over six square miles, exclusive of piers, and contained, according to the
census of 1880, a population of 813,076. This gives 208 persons per acre.
The census of 1880 reports the total number of dwellings in New York at
73,684; total population, 1,206,299; average per dwelling, 16.37. Selecting
for comparison an area about equal from the fifteen most densely populated
districts or parishes of London, of an aggregate area of 3,896 acres, and
with a total population of 746,305, we obtain 191.5 persons per acre. Thus
briefly New York averaged 208 persons per acre, and 16.37 per dwelling;
London, for the same area, 191.5 persons per acre, and 7.21 per house. But
this comparison is scarcely fair, as in London only the most populous and
poorest districts are included, corresponding to the entirely tenement
districts of New York, while in the latter city it includes the richest and
most fashionable sections, as well as the poorest. If tenement districts
were taken alone, the population would be found much more dense, and New
York proportionately much more densely populated. Taking four of the most
thickly populated of the London districts (East London, Strand, Old Street,
St. Luke's, St. Giles-in-the-Fields, and St. George, Bloomsbury), we find
on a total area of 792 acres a population of 197,285, or an average of 249
persons per acre. In four of the most densely populated wards of New York
(10th, 11th, 13th, and 17th), we have on an area of 735 acres a population
of 258,966, or 352 persons per acre. This is 40 per cent. higher than in
London, the districts being about the same size, each containing about
1-1/5 square miles. Apart from the greater crowding which takes place in
New York, and the different style of buildings, another very fertile cause
of the spreading of fires is the freer use of wood in their construction.
It is asserted that in New York there is more than double the quantity of
wood used in buildings per acre than in London. From a house census
undertaken in 1882 by the New York Fire Department, moreover, it appears
that there were 106,885 buildings including sheds, of which 28,798 houses
were built of wood or other inflammable materials, besides 3,803 wooden
sheds, giving a total of 32,601 wooden buildings.
We are not aware that there are any wooden houses left in London. There are
other minor causes which act as checks upon the spreading of fires in
London. London houses are mostly small in size, and fires are thus confined
to a limited space between brick walls. Their walls are generally low and
well braced, which enable the firemen to approach them without danger.
About 60 per cent. of London houses are less than 22 feet high from the
pavement to the eaves; more than half of the remainder are less than 40
feet high, very few being over 50 feet high. This, of course, excludes the
newer buildings in the City. St. James's Palace does not exceed 40 feet,
the Bank of England not over 30 feet in height; but these are exceptional
structures. Fireproof roofings and projecting party walls also retard the
spreading of conflagrations. The houses being comparatively low and small,
the firemen are enabled to throw water easily over them, and to reach their
roofs with short ladders. There is in London an almost universal absence of
wooden additions and outbuildings, and the New York ash barrel or box kept
in the house is also unknown. The local authorities in London keep a strict
watch over the manufacture or storage of combustible materials in populous
parts of the city. Although overhead telegraph wires are multiplying to an
alarming extent in London, their number is nothing to be compared to their
bewildering multitude in New York, where their presence is not only a
hinderance to the operations of the firemen, but a positive danger to their
lives. Finally--and this has already been partly dealt with in speaking of
the comparative density of population of the two cities--a look at the map
of London will show us how the River Thames and the numerous parks,
squares, private grounds, wide streets, as well as the railways running
into London, all act as effectual barriers to the extension of fires.
The recent great conflagrations in the city vividly illustrate to Londoners
what fire could do if their metropolis were built on the New York plan. The
City, however, as we have remarked, is an exceptional part of London, and,
taking the British metropolis as it is, with its hundreds of square miles
of suburbs, and contrasting its condition with that of New York, we are led
to adopt the opinion that London, with its excellent fire brigade, is safe
from a destructive conflagration. It was stated above, and it is repeated
here, that the fire brigade of New York is unsurpassed for promptness,
skill, and heroic intrepidity, but their task, by contrast, is a heavy one
in a city like New York, with its numerous wooden buildings, wooden or
asphalt roofs, buildings from four to ten stories high, with long unbraced
walls, weakened by many large windows, containing more than ten times the
timber an average London house does, and that very inflammable, owing to
the dry and hot American climate. But this is not all. In New York we find
the five and six story tenement houses with two or three families on each
floor, each with their private ash barrel or box kept handy in their rooms,
all striving to keep warm during the severe winters of North America. We
also find narrow streets and high buildings, with nothing to arrest the
extension of a fire except a few small parks, not even projecting or
effectual fire-walls between the several buildings. And to all this must be
added the perfect freedom with which the city authorities of New York allow
in its most populous portions large stables, timber yards, carpenters'
shops, and the manufacture and storage of inflammable materials. Personal
liberty could not be carried to a more dangerous extent. We ought to be
thankful that in such matters individual freedom is somewhat hampered in
our old-fashioned and quieter-going country.--_London Morning Post_.
* * * * *
THE LATEST KNOWLEDGE ABOUT GAPES.
The gape worm may be termed the _bete noir_ of the poultry-keeper--his
greatest enemy--whether he be farmer or fancier. It is true there are some
who declare that it is unknown in their poultry-yards--that they have never
been troubled with it at all. These are apt to lay it down, as I saw a
correspondent did in a recent number of the _Country Gentleman_, that the
cause is want of cleanliness or neglect in some way. But I can vouch that
that is not so. I have been in yards where everything was first-rate, where
the cleanliness was almost painfully complete, where no fault in the way of
neglect could be found, and yet the gapes were there; and on the other
hand, I have known places where every condition seemed favorable to the
development of such a disease, and there it was absent--this not in
isolated cases, but in many. No, we must look elsewhere for the cause.
Observations lead me to the belief that gapes are more than usually
troublesome during a wet spring or summer following a mild winter. This
would tend to show that the egg from which the worm (that is in itself the
disease) emerges is communicated from the ground, from the food eaten, or
the water drunk, in the first instance, but it is more than possible that
the insects themselves may pass from one fowl to another. All this we can
accept as a settled fact, and also any description of the way in which the
parasitic worms attach themselves to the throats of the birds, and cause
the peculiar gaping of the mouth which gives the name to the disease.
Many remedies have been suggested, and my object now is to communicate some
of the later ones--thus to give a variety of methods, so that in case of
the failure of one, another will be at hand ready to be tried. It is a
mistake always to pin the faith to one remedy, for the varying conditions
found in fowls compel a different treatment. The old plan of dislodging the
worms with a feather is well known, and need not be described again. But I
may mention that in this country some have found the use of an ointment,
first suggested by Mr. Lewis Wright, I believe, most valuable. This is made
of mercurial ointment, two parts; pure lard, two parts; flour of sulphur,
one part; crude petroleum, one part--and when mixed together is applied to
the heads of the chicks as soon as they are dry after hatching. Many have
testified that they have never found this to fail as a preventive, and if
the success is to be attributed to the ointment, it would seem as if the
insects are driven off by its presence, for the application to the heads
merely would not kill the eggs.
Some time ago Lord Walsingham offered, through the Entomological Society of
London, a prize for the best life history of the gapes disease, and this
has been won by the eminent French scientist M. Pierre Megnin, whose essay
has been published by the noble donor. His offer was in the interest of
pheasant breeders, but the benefit is not confined to that variety of game
alone, for it is equally applicable to all gallinaceous birds troubled with
this disease. The pamphlet in question is a very valuable work, and gives
very clearly the methods by which the parasite develops. But for our
purpose it will be sufficient to narrate what M. Megnin recommends for the
cure of it. These are various, as will be seen, and comprise the experience
of other inquirers as well as himself.
He states that Montague obtained great success by a combination of the
following methods: Removal from infested runs; a thorough change of food,
hemp seed and green vegetables figuring largely in the diet; and for
drinking, instead of plain water, an infusion of rue and garlic. And Megnin
himself mentions an instance of the value of garlic. In the years 1877 and
1878, the pheasant preserves of Fontainebleau were ravaged by gapes. The
disease was there arrested and totally cured, when a mixture, consisting of
yolks of eggs, boiled bullock's heart, stale bread crumbs, and leaves of
nettle, well mixed and pounded together with garlic, was given, in the
proportion of one clove to ten young pheasants. The birds were found to be
very fond of this mixture, but great care was taken to see that the
drinking vessels were properly cleaned out and refilled with clean, pure
water twice a day. This treatment has met with the same success in other
places, and if any of your readers are troubled with gapes and will try it,
I shall be pleased to see the results narrated in the columns of the
_Country Gentleman_. Garlic in this case is undoubtedly the active
ingredient, and as it is volatile, when taken into the stomach the breath
is charged with it, and in this way (for garlic is a powerful vermifuge)
the worms are destroyed.
Another remedy recommended by M. Megnin was the strong smelling vermifuge
assafoetida, known sometimes by the suggestive name of "devil's dung." It
has one of the most disgusting oders possible, and is not very pleasant to
be near. The assafoetida was mixed with an equal part of powdered yellow
gentian, and this was given to the extent of about 8 grains a day in the
food. As an assistance to the treatment, with the object of killing any
embryos in the drinking water, fifteen grains of salicylate of soda was
mixed with a pint and three-quarters of water. So successful was this, that
on M. De Rothschild's preserves at Rambouillet, where a few days before
gapes were so virulent that 1,200 pheasants were found dead every morning,
it succeeded in stopping the epidemic in a few days. But to complete the
matter, M. Megnin adds that it is always advisable to disinfect the soil of
preserves. For this purpose, the best means of destroying any eggs or
embryos it may contain is to water the ground with a solution of sulphuric
acid, in the proportion of a pennyweight to three pints of water, and also
birds that die of the disease should be deeply buried in lime.
Fumigation with carbolic acid is an undoubted cure, but then it is a
dangerous one, and unless very great care is taken in killing the worms,
the bird is killed also. Thus many find this a risky method, and prefer
some other. Lime is found to be a valuable remedy. In some districts of
England, where lime-kilns abound, it is a common thing to take children
troubled with whooping-cough there. Standing in the smoke arising from the
kilns, they are compelled to breathe it. This dislodges the phlegm in the
throat, and they are enabled to get rid of it. Except near lime-kilns, this
cannot be done to chickens, but fine slaked lime can be used, either alone
or mixed with powdered sulphur, two parts of the former to one of the
latter. The air is charged with this fine powder, and the birds, breathing
it, cough, and thus get rid of the worms, which are stupefied by the lime,
and do not retain so firm a hold on the throat. An apparatus has recently
been introduced to spread this lime powder. It is in the form of an
air-fan, with a pointed nozzle, which is put just within the coop at night,
when the birds are all within. The powder is already in a compartment made
for it, and by the turning of a handle, it is driven through the nozzle,
and the air within the coop charged with it. There is no waste of powder,
nor any fear that it will not be properly distributed. Experienced pheasant
and poultry breeders state that by the use of this once a week, gapes are
effectually prevented. In this case, also, I shall be glad to learn the
result if tried.
STEPHEN BEALE.
H----, Eng., Aug. 1.
--_Country Gentleman_.
* * * * *
WOLPERT'S METHOD OF ESTIMATING THE AMOUNT OF CARBONIC ACID IN THE AIR.
There is a large number of processes and apparatus for estimating the
amount of carbonic acid in the air. Some of them, such as those of
Regnault, Reiset, the Montsouris observers (Fig. 1), and Brand, are
accurate analytical instruments, and consequently quite delicate, and not
easily manipulated by hygienists of middling experience. Others are less
complicated, and also less exact, but still require quite a troublesome
manipulation--such, for example, as the process of Pettenkofer, as modified
by Fodor, that of Hesse, etc.
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