face reducing the amount of waste heat
passing away, and this proves that fiame
contact, and therefore quick absorption
of heat, takes place on plain surfaces as
soon as these are above a certain tem-
perature which, in a metal ladle, very
soon occurs. What the temperature is
which admits of flame contact I have, as
yet, not been able to test thoroughly,
and it will need some consideration how
the determination of this is to be cor-
rectly made; at the same time it is a
question in physics which should be cap-
able of being answered. Let us now
take the other side of the question. If
the efficiency of a surface depends on
flame contact, there must of coui'se be
flame, or at least gases of an extremely
high temperature, and we tlerefore can-



not expect this extraordinary increase of
efficiency in any part of our boiler ex-
cept where flame exists, and if these pro-
jections are placed in a boiler, anywhere
except in contact with flame, their effi-
ciency must be reduced to that of ordi-
nary heating sui-face. They are, of
course, useful, but only in the same w^j
as ordinary flue surface. When we come
to boilers for raising steam, which have
to stand high pressures, we come to
other difficulties of a very serious nature,
which require special provision to over-
come them. To put such rods as I have
referred to in a boiler-plate necessitates
the plate being drilled all over with
holes, causing a dangerous source of
weakness, as the rods cannot be used as
stays ; further than this, they would
render really efficient examination a mat-
ter of extreme difficulty, and would be
liable to give rise to frequent and almost
incurable leakages ; but there is, fortu-
nately, a very simple way to overcome
this difficulty. I have found that rods
or points, such as I have described, are
not necessary, and that the same results
can be obtained by webs or angle-ribs
rolled in the plates. My experiments in
this direction are not complete, and at
present they tend to the conclusion that
circular webs, which would be of the
greatest efficiency in strengthening the
flues, are not so efficient for heating as
webs running lengthways with the flue,
and in a line with the direction of the
flame. This point is one which I am at
present engaged in testing with experi-
mental boilers of the Cornish and Lan-
cashire type, and, as we have in gas a
fuel which renders every assistance to the
experiment, it will not take long to prove
the comparative results obtained by the
two different forms of web. Those of
you who have steam boilers will, no
doubt, know the great liability to crack-
ing at the rivet holes in those parts
where the plates are double ; this crack-
ing, so far as my own limited experience
goes, being usually, if not always, on the
fire side, where the end of the plate is
not in direct contact with the water,
where it is, in fact, under the conditions
of one of the proposed webs. I think
we may safely come to the conclusion
that this cracking is caused by the great
comparative expansion and contraction
of the edge of the plate in contact with



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CHOLERA IN ITS RELATION TO WATER SUPPLY.



141



the fire, and it will probably be found
that if the plates are covered with webs,
the whole of the surface of the plates
will be kept at a higher and more uni-
form temperature, and the tendency to
crack at the rivet-holes will be reduced.
This is a question not entirely of theory,
but needs to be tested in actual practice.
There is another point of importance in
boilers of the locomotive class, and those
in which a very high temperature is kept
in the fire-box, and this is the necessity
of determining by direct experiment the
speed with which heat can safely be con-
ducted to the water without causing the
evolution of steam to be so rapid as to
prevent the water remaining in contact
with the plates, and also whether the
steam will or will not carry mechanically
with it so much water as to make it objec-
tionably wet, and cause priming and loss
of work by water being carried into the
cylinders. I have observed, in the open
boilers L use, that when sufficient heat is
applied to evaporate one cubic foot of
water per hour from one square foot of
boiler surface, the bulk of the water in
the vessel is about doubled, and that the
water holds permanently in suspension a
bulk of steam equal to itself. I have, as
yet, not had sufficient experience to say
anything positively as to the formation
or adhesion of scale on such surfaces as
I refer to, but the whole of my experi-
mental boilers have, up to the present,
remained bright and clean on the water
surface, being distinctly cleaner than the
boiler used with ordinary flat surfaces.



It is, I believe, generally acknowledged
that quick heating and rapid circulation
prevent, to some extent, the formation
of hard scale, and tliis is in perfect
accord with the results of my experi-
ments. The experiment which I have
shown you, I think, demonstrate beyond
all question that the steaming power of
boilers in limited spaces, such as our sea-
going ships, can be greatly increased ;
and when we consider how valuable space
is on board ship, the matter is one worthy
of serious study and experiment. It
may be well to mention that some appli-
cations of this theory are already
patented. I will now show you as a
matter of interest in the application of
coal gas as a fuel, how quickly a small
quantity of water can be JjoiJed by a
kettle constructed on the principle I
have described, and to make the experi-
ment a practical one I will use a heavv
and strongly-made copper kettle which
weighs 6^ lbs., and will hold when full
one gallon. In this kettle I will boil a
pint of water, and, as you see, rapid
boiling takes place in 60 seconds. The
same result could be attained in a light
and specially made kettle in 30 seconds,
but the experiment would not be a fair
practical one, as the vessel used would
not be fit for hard daily service, and I
have therefore limited myself to what
can be done in actual daily work rather
than laboratory results, which, however
interesting they may be, would not be a
fair example of the apparatus in actual
use at present.



CHOLERA IN ITS RELATION TO WATER SUPPLY.



Bt GBORGB HIGGIN.
From "Nature."



The epidemic of Asiatic cholera, which
has been raging in Spain during the last
two years, and which appears even yet
to be lurking in some portions of that
peninsula, has furnished some interesting
data as regards its connection with water
supply, to which it would be wise in us
to direct our attention, not only from the
interesting nature of the facts as such,
but also because it is not improbable that



ere the disease quits Europe it may visit
our own shores.

Broadly speaking, it would appear that
in Spain this formidable disease never
became truly epidemic or dangerous in
any city in which there was a pure and
good supply of water, and proper means
were taken to guard against the sources
being polluted by any of the specific
choleraic poison.



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VAN NOSTRAND's ENGINEERING MAGAZINE.



In support of this idea I would desire
to call attention to the cities of Toledo,
Seville, Malaga, and Madrid, in contra-
distinction to such places as Aranjuez,
Saragossa, Oranada, and Valencia. I will
commence with Madrid. This city,
whose population at the last census was
397,816, suffered very severely, indeed,
under the last epidemic of 1865, when
during several days immediately follow-
ing a very severe thunderstorm, the num-
ber of cases varied from 800 to 1,200
per day. The first invasion of last year
took place in Madrid on May 20, and the
disease ran its course during the whole
of the summer, gradually disappearing
towards the end of the month of Sep-
tember. The total number of cases dur-
ing the whole of the period was 2,207,
and the deatfab 1,366. The total number
of cases, therefore, during the five
months that the disease never abandoned
the city was barely more than what oc-
curred during two days only of the epi-
demic of 1865, being little more than ^
per cent, of the population. I think,
therefore, we may safely eay that the
disease never assumed a truly epidemic
form. The greatest number of cases, as
was to be expected, took place during
the months of July and August ; the first
notable increase took place on July 25,
and the first notable decrease on August
13.

In connection with this it is interest-
ing to note that Madrid was subject to
severe thunderstorms during the latter
end of July, and that 119 miUimeters of
rain fell during the month. These
storms began on the 13th, and were espe-
cially severe on the 23d, 24th, 26th, 27th,
and 31st, the first notable rise in the
cases of cholera occurring between the
25th and 28th. As a general rule, no
rain falls in Madrid in July, and the oc-
currence of these severe thunderstorms
and heavy falls of rain was quite phe-
nomenal.

The new water supply from the Guada-
rama Mountains was completed shortly
before 1865, and the greater part of the
drainage was also finished ; but at that
time the new water supply had scarcely
come into use, the large majority of the
houses being supplied from the old foun-
tains which existed in various parts of
the city. During the last twenty years
the use of the Lozoya water has become I



very general, and an ample supply has
been provided for washing the streets
and flushing the sewers.

Madrid is now well drained ; the sewers
are built upon the Paris model, and are
not what an English engineer would con-
sider as a good type for self-cleansing
purposes, but the fall is, in almost every
case, very great, and it is not probable
that there can be any collection of fcecal
matter at any point. The connection of
the street gullies with the main sewers is
made without any trap, and good ventila-
tion is thus provided. As regards the
outfall of these sewers, nothing satisfac-
tory can be said. The mouths of the
main sewers, which are seven in number,
all discharge on the southern side, be-
tween the station of the Saragossa Rail-
way and that of the Northern.

The question of the proper disposal
of the sewage in Madrid, as in London,
has never been decided, and pending this
decision the sewers were completed only
as far as the outlying houses of the city,
and the sewage was then allowed to find
its way down to the Manzanares, in the
best way it cuuld. During the time the
question has been awaiting a solution the
town has extended, and houses have been
built along the course of these open
sewers. As might have been expected,
the first serious outbreak of cholera oc-
curred about these spots, the original
germ of the disease having been im-
ported from the neighborhood of Valen-
cia, where the cholera was then raging.

The existence of the disease having
been established beyond doubt, one of
the first acts of the Municipality was to
attend to the water supply. There ex-
isted ] 1 ancient sources, which supplied
85 taps or fountaiuF, 22 of which were
public ones, at which water-carriers were
allowed to fill their barrels, and the re-
maining 63 belonged to groups of houses.
In spite of the excellent supply brought
in from the Lozoya, these old sources
were still a good deal used by the inhabi-
tants — many, from old habits, preferring
to use the same water which their fathers
had used, many not being willing to in-
cur the expense of laying on the new
supply. In view of the impossibility of
effectually guarding against the possible
contamination of so many sources of sup-
ply, the Municipality, by decree, on June
18, closed all the old ones, with the ex-



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CHOLERA IN ITS RELATION TO WATER SUPPLY.



143



ception of that of La Fuente de la Beina,
which supplied five public fountains and
four private ones, llie Central Govern-
ment undertook the custody of the Lo-
zoya aqueduct, the Municipality took
charge of the Fuente de la Reina. The
Lozoya water is drawn from the sources
of the River Lozoya in the Guadarama
Mountains, some 50 miles to the north
of Madrid.

The river takes its rise in the granite
formation; the water is excellent, and
from the uninhabited condition of the
country through which the river flows
before the intake, it is not exposed to
direct contamination from any specific
poison. From the intake to Madrid the
water is conducted by a series of mag-
nificent works, partly covered, partly un-
covered, to Madrid, where it is received
in covered reservoirs before being dis-
tributed in the city ; the service is con-
tinuous, no cisterns being used. During
the whole time of the existence of cholera
in the city the uncovered portion of the
aqueduct was patroled by armed guards,
no one being permitted to approach with-
out a special order.

Accompanying the extensive report of
Madrid, Don Alberto Bosch, amongst
other plates, is an excellent map of the
city, showing, by a red dot, the situation
of every case of cholera that occurred ;
they are seen pretty thickly scattered
about the uncovered exits of the sewers,
and on both sides of the River Manza
nares, which is, in fact, in summer, an
open sewer, and in the lower portion of
the city overlooking the river, and there
is scarcely any part of the town where a
dot is not to be found ; but, with the ex-
ception of the points mentioned, the
cases occurring in the remainder of the
town seem to be all isolated ones ; in ex-
tremely few cases do two dots occur to-
gether, showing that the disease was
more of a sporadic than of an epidemic
character.

Now let us take the case of Toledo.
This ancient capital of Spain is certainly
not a city that could be taken as a model
of sanitary arrangements ; on the con-
trary, it seem to be admii'ably adapted
to form a good nest for any wandering
epidemic, and yet, although the cholera
entered it in the summer of 1884, and
did not finally leave it till the autumn of
1886, the total number of cases, accord-



ing to official returns, did not exceed 200,
of which about one-half were fatal. The
population of Toledo is over 20,000, so
that the percentage of choleraic disease
was only about 1 per cent, of the popu-
lation for the two seasons.

Toledo was supplied with water from the
river Tagus, which flows round the city,
the water being lifted by pumps. Above
Toledo on the same liver, is situated
Aranjuez, and above Aranjuez again, on
the Manzanares, which is a feeder of the
Tagus, is situated Madrid, in both of
which towns the cholera existed in 1885,
being unusually severe in Aranjuez. The
Governor of the province, recognizing
the suspicious character of the wat<:*r,
stopped the pumps, and obliged the in-
habitants to send for their drinking
water to a distant spring ; he even for-
bade anyone to bathe or wash clothes in
the river. The measure was a strong one,
but it saved the city.

Let us next take Seville. Seville is an
important city, the third in rank in
Spain ; it contains, according to the cen-
sus of 1877, 134,318 inhabitants ; it has,
strictly speaking no drainage; a few an-
cient sewers exist for carrying off the
mnwater from the lower portion of the
city, but sewerage for houses does not
exist. The sewage goes into cesspools,
which are, in most cases, situated just
outside the house, and under the street ;
the inhabitants are extremely cleanly in
their habits, and the outsides of their
dwellings are constantly whitewashed,
but it is not a healthy city — typhoid fever
is endemic, and the death rate rises in
some parishes to 35 per mil.

Seville is situated on the river Giiadal-
quiver, of which the rivers Darro and
Genii, that flow through Granada, are
feeders ; as regards its water-supply, one
suburb of the city, called Triana, con-
taining about 30,000 inhabitants, is sit-
uated on the western side of the river.
This portion is almost entirely inhabited
by the poorer, class, and they drink gen-
erally the water of the river.

The rest of the town is supplied from
an ancient Roman or Moorish aqueduct,
the water being brought from an under-
ground spring near the town of Alcala,
about nine miles to the east of Seville ;.
this water is carried by a tunnel about two-
miles in length under the town of Alcala;:
it is then carried in a covered conduit to



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144



VAN NOSTBAND'S ENGINEERING MAGAZINE.



within a short distance of Seville, and
from thence by an aqueduct made by the
old Moors. The water is excellent

An English company has quite lately
erected engines at Alcala, by means of
which they pump up to a covered reser-
voir above the town, the water from two
other springs, situated also at Alcala,
but on the opposite side of the river
Ouadaira, which flows past the town.
This water is carried from the reservoir
into the town by iron pipes, and distrib-
uted under considerable pressure; in
character it is pure and excellent ; the
springs rise from the base of the sand-
stone at a short distance from the en-
^ne house, and are carried across the
river by an iron pipe. The cholera
broke out in Oranada on July 14,
1885, but already on June 14 of the
same year the authorities of Seville,
by way of prevision, had prohibited the
use of any water from the river, either
for dietetic or other purposes ; had au-
thorized the English company to lay a
temporary pipe across the bridge which
connected the city with the Triana sub-
urb, and had opened a number of free
taps from which the inhabitants of this
suburb could draw the new water.

The old Moorish supply was scarcely
susceptible of contamination, as the con-
duit was covered for the greater part of
way, and where it ran over the aqueduct
no one but the Municipal guards had
-ever been allowed to pass ; guards, how-
•ever were stationed day and night on the
springs from which the English company
derived their water, and no one was al-
lowed to approach them without permis
sion.

The cholera raged fearfully in Granada
during the months of July, August, and
September; it descended the River
Oenil, which runs through Granada, and
attacked the towns of Herera, Ecija, and
others in the province of Seville. It
broke out also at Cordova and other
towns on the Guadalquivir, of which the
Genii is an affluent, and it broke out in
Palma, XJtrera, Puerto Real, Puerto
Santa Maria, and Cadiz, forming a circle
around Seville, but the city itself escaped
almost completely. Towards the end of
September nine cases occurred in one
quarter of the city, of which seven were
fatal, but the disease did not spread ;
none of the five houses in which these



cases occurred were connected on to the
water supply, and it is possible they
may have used well or river water, al-
though this is not known. Jerez, which
lies about half-way between Seville and
Cadiz, and close to the town of Puerto
Santa Maria, which was attacked by
cholera, escaped also from the disease.
This town possesses a very excellent
water-supply, brought down some few
years ago from a spring in the moun-
tains by a native company, at a cost of
£300,000.

Malaga has a population of 115,882.
This city is in even a worse sanitary con-
dition than Seville as regards its drain-
age, and a great deal worse as regards
its cleanliness. In the old portion of
the town the streets are narrow, unventi-
lated, and intolerably filthy ; the climate
in summer is almost tropical.

It is difficult to obtain reliable data as
to the cases of cholera in Malaga, as at-
tempts were made to prove that no real
cholera existed in Malaga ; but there can
be no doubt but that from June to Sep-
tember the cholera did exist, and it is
probable that during the whole of the
summer there occurred some 200 or 300
real cases of Asiatic cholera. But the
disease never became epidemic, although,
to all appearances the city offered a most
excellent medium for the propagation
of the disease, and on all former visita-
tions had suffered very severely. But
Malaga, during the last few years, has
been provided with an excellent water-
supply drawn from some springs situated
at Torremolinas, on the coast to the
westward of the city, and piped from
thence into the city ; and although the
precautions adopted were not so com-
plete as those at Seville, yet a more or
less successful attempt was made to pre-
vent the use of any other water than that
brought from Torremolinas.

We have now examined the case of the
few towns in Spain that possess a pure
supply of water drawn from springs not
liable to any specific contamination, and
we have seen that in all cases where such
a supply existed, the cholera, although
present in all of them,. never made any
headway, or became truly epidemic, al-
though in every case, except that of
Madrid, there was no proper drainage,
and the sanitary conditions were in many
cases as bad as they could be.



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CHOLEBA IN ITS RELATION TO WATEDR SUPPLY.



145



Let us now look on the other side of
the picture. We will commence with
Oranada — population 76,006. As re
gards its sanitary arrangements, this city
is on a par with Malaga; about one-
tenth of the town is drained, but the
sewers are of a very inferior class. The
<!ity is supplied with water by canals de-
rived from the Genii and Darro, the two
rivers which serve to irrigate the mag-
iiificent plain which speads around it.
A small portion is supplied from a spring
called La Fuente Grande de Alfacar.
The canals are uncovered and exposed to
all kinds of contamination.

Through the streets the water is con-
ducted in earthenware pipes, after the
style of the Moors ; many of the pipes
are the original ones put down by these
people before the conquest of the city by
Perdinand and Isabella. The cholera
broke out about the middle of July. It
is supposed to have first been brought in
by some laborers who had arrived from
Mui'cia, where the cholera was raging.
It spread with frightful rapidity, and by
the middle of August the official number
of cases reported was over 450 per
day. It died out, or rather wore itself
out, about the middle of September. The
total official returns give a total of 6,471
cases, and 5,093 deaths, but in the city
itself these returns are said to be much
under-estimated; some, indeed, say the
numbers should be doubled.

No attempt was made, as was done at
Toledo with such excellent results, to
suppress the old water supply, and the
epidemic took in a short time such alarm-
ing proportions that the local authori-
ties were completely paralyzed. It was
difficult to carry on the interment of the
bodies, and at one time from 400 to 500
corpses were lying piled up in the ceme-
tery awaiting interment

The coui*se of the cholera may be fol-
lowed down the rivers Darro and Genii,
the infected waters carrying death wher-
ever they were used for drinking pur-
purposes.

Murda — population 91,805 — from
which the cholera was imported into
Granada, suffered heavily also. It was
carried into the plains of Murcia by the
waters of the river Segura, from' the
baths of Archena, and it was imported
into Archena by some invalid soldiers
who were sent to the baths from the in-



fected district around Valencia. The
plain of Murcia is irrigated by the waters
of the Segura, and the disease com-
menced in this district with the death of
a laborer who had drunk the water of
one of the irrigation channels. The in-
habitants of Murcia and of the plain use
principally water from the irrigation
canals or from the river ; this water is
usually stored in large jars similar to
those which held Ali Baba and his forty
thieves, and among well-to-do people it
is customary to keep a year's supply in
hand ; that is to say, the water is allowed
to repose for one year, before use, in a
reservoir or "algibe," constructed on
purpose, or in some of these large jars
sunk up to their necks in the ground ; by
this means it becomes perfectly clear, cool,
and palatable. The poorer classes are, as
a matter of course, not able to take these
precautions, and have to drink the water
from the canals, or after a few days' re-
pose only.

The epidemic raged principally amongst
the little cottages scattered thickly over
the plain, or garden, as it is called, but
the disease never developed itself in
Murcia as it did in Granada, and the city
itself escaped better than might have
been expected. May this not be attrib-
uted to the fact that the greater part of