5>o26f.A

MEMOIRS

OF THE

LITERARY AND PHILOSOPHICAL SOCIETY

or

MANCHESTER.

P-^^^A./S-

MEMOIRS

LITERARY

PHILOSOPHICAL SOCIETY

MANCHESTER.

^(conti Set(e».

VOLUME TENTH.

LONDON:

H. BAILLIERE, PUBLISHER, 219, REGENT STREET,

AND 290, BROADWAY, NEW YORK.

PARIS: .). B. BAILLIERE, LIBRAIRE, RUE HAUTEFEUILLE.

1852.

Cavf. & SKvt:R, Printers, Pa'atine Buildings, Hunt's Bank, Manchester.

NOTE.

The Authors of the several Papers contained in this
Volume, are themselves accountable for all the statements
and reasonings which they have offered. In these parti-
culars the Society must not be considered as in any way
responsible.

CONTENTS.

Abticlk Page

I. — On the Causes of the great Currents of the Ocean. B\- Mr.

Alderman Hopkins 1

II. — Some Remarks on " The Deserted Village" of Goldsmith. By

Mr. J. Y. Caw 17

III. — A New Discussion of the General Equation of Curv'es of the

Second Degree. By Mr. Eobert Finlay 33

IV. — On the Origin and Nature of the Forces that produce Storms.

By Mr. Hopkins 69

V. — Contributions to the Knowledge of the Manufacture of Gas. By

Dr. E. Fbankland 71

VI. — Notes on the Drift Deposits found near Blackpool. By Mr. E.

W. BiNNEY 121

VII. — Some Account of the Floods which occurred at the Manchester
Waterworks in the month of February, 1852. By Mr. J. F.
Bateman 1.37

VIII. — On the Identity of Light, Heat, Electricity, Magnetism, and

Gravitation. By J. Goodman, M.D I55

IX. — On the economical production of Mechanical EflFect from Che-
mical Forces. By Mr. J. P. Joule I73

X. — On some Trails and Holes found in Rocks of the Carboniferous
Strata, with remarks on the Microconchus Carbonarius. By
E. W. BiNNEY 181

XI. — A Biographical Notice of Peter Clare, Esq., F.R.A.S. By the

Rev. Henry Halfobd Jones 203

XII. — On the Air and Rain of Manchester. By R. Angus Sjoth 207

List of Donations 219

List of Members 223

MEMOIRS

OT TBE

%iUxav)^ anlr ^^ilo^o^f^itnl Botitt^ of

I. — On the Causes of the Great Currents of the Ocean.
By Mr. Alderman Hopkins.

[Read Nwemher ith, 18S1 .]

In addition to the disturbances produced in the water of the
ocean by tidal action, there are extensive movements of it
that are known by the name of Oceanic Currents. Different
opinions have been entertained respecting the causes of these
currents, but they have generally been ascribed to the rotation
of the globe on its axis causing the surface of the earth to
move eastward, faster than the water which is contained in
the bed of the ocean. The influence of wind on the surface
of the water has been occasionally recognised, but mostly as
a modifying cause, affecting only the surface and the water
immediately under it.

For instance, in Lizars' Atlas, which is a popular compilation
from what are considered the best authorities, it is said, —
" Besides the tides there is a regular motion of the whole
waters of the ocean, which carries them from east to west in
the tropical regions, and as far as 30 degrees of north and
south latitudes in the same direction as the trade winds.

ON THE CAUSES OF THE

but contrary to that of the rotation of the globe."
According to Malte-Brun — "The globe, moving with velocity
towards the east, leaves the waters of the tropical oceans
always a little behind ; and hence they seem to move
towards the west with a rapidity proportioned to the
superior velocity with which the solid parts of the earth
really move towards the east." And the writer of the Atlas
remarks — " Whatever may be thought of this theory, which
it must be confessed is somewhat fanciful, the fact is certain
as to the existence of these currents or movements, by
which the waters of the sea are carried without any impulse
of the wind or tide into a particular direction." " Thus the
Pacific Ocean flows from east to west with a motion powerful
in proportion to the vast and uninterrupted extent of that
sea. This main current in its motion westward is impeded
by an immense archipelago of islands and sub-marine moun-

fr tains. It forces its way into this labyrinth, and then forms a

^* variety of currents." — (p. 35.)

In the same work, in speaking of the Atlantic currents it is
said — " The great western current of the Indian Ocean, after
passing the Cape of Good Hope, advances across the Atlantic
to the American shore; and being opposed by this great
barrier the waters divide, and are turned in different
directions by the peculiar configurations of the coast. One
part makes its way through the Straits of Magellan to the
Pacific Ocean ; the other stream is better known, it being
the great current of the Atlantic Ocean, which is turned
northward about the 8th degree of south latitude, and
extends towards the eastern coast of America. It is ex-
tremely rapid; — it prevails from the 30,th degree of north
latitude to the 10th degree of south latitude, beginning at
from twenty to thirty leagues from the coast of Africa, and
extending over all that sea in which the Antilles are
scattered. There is a third great current of the Atlantic
Ocean, by which its waters, in their progress westward, are

GBEAT CURRENTS OF THE OCEAN.

3

carried violently into the Gulf of Mexico, and there, being
collected and concentrated, they rush with rapidity through
the Bahama Channel."

In the Penny Cyclopaedia, where the general opinion on the
subject is also given, it is said that " Humboldt, ascribing the
formation of these currents to the rotation of the earth,
calls them ' currents of rotation.' But he does not dis-
tinguish between the proper currents and the drift water,
which latter produces a slight western current on the surface
of the ocean between the tropics. This latter motion is
indeed probably caused by the united effects of the rotation
and the trade winds, on the wide-expanded surface of the
ocean. The small degree of velocity in this current, how-
ever, shews that the stronger currents near the equator
cannot arise from the same cause. Rennel thinks that the
equatorial currents are caused by the accumulation of great
masses of drift-water near the equator, by the north-easterly
and south-easterly trade winds. But this opinion will be
found inadmissible, when it is considered that such accu-
mulation could only produce a superficial current ; and
these currents are not superficial, but go to a great depth."
Again, in the article on this subject in the Encyclopaedia
Britannica it is said, that " in the sea, currents are either
natural and general, arising from the diurnal rotation of the
earth about its axis; or accidental and particular, caused
by the waters being driven against promontories, or into
gulfs or straits."

Thus, all these writers concur in representing the rotatory
motion of the earth as the great cause of the oceanic currents
that are found within the tropical regions. This rotatory
motion causing the tropical parts of the land to move east-
ward at a high velocity, as it undoubtedly does, it is assumed
that the waters of the ocean must be left behind. But for
this assumption there does not appear to be any sufiicient
reason assigned, nor indeed is any plausible reason given,

4

ON THE CAUSES OF THE

unless the alleged depths of the oceanic currents can be con-
sidered one. But it will be admitted that the weight of the
water will cause it to press on the solid bottom of the sea,
however deep or shallow the water may be, with a force
proportioned to the weight ; and it has not been shewn that
that weight will be insufficient to enable the solid earth to
carry the fluid water with it, and thus to cause both to move
with a velocity which, with reference to our present subject,
may be considered equal. The assumption, therefore, that
the water will be left behind the land, being unsupported by
specific evidence, may at present be treated as unproved and
unfounded. Of the facts that are furnished there is no doubt,
as these oceanic currents are well known to exist ; it is there-
fore of the causes alone that we have to treat, and the great
cause is stated by these writers to be the rotation of the
surface of the globe making the solid land move faster than
the liquid water that rests upon it, which is therefore said to
be left behind in its rotation, making an apparent current.

Now, if the rotation of the solid earth really left the water
behind, we should have an apparent western current flowing
across every part of the open tropical seas, and therefore
across not only the Pacific and Atlantic, but also across the
Indian Ocean, near the Equator, say from Sumatra to Ajan
and Zanguebar on the eastern side of Africa. This ocean is
as wide as the Atlantic near to the equator, and therefore
would allow the land to pass eastward from the water, if it
could so pass, quite as well as in the Atlantic. But there is
no such current in this- part of the Indian Ocean; on the
contrary, the currents that are found in this locality flow
towards the east rather than to the west. •

On the opposite side of the Continent of Africa, however,
there is a very decided oceanic current, but it flows from the
west to the east, just in the opposite direction to those
" currents of rotation" of which we have been speaking. This
current is generally spoken of as being very extraordinary.

GREAT CURRENTS OF THE OCEAN. O

Lizars says of it, — " Along the western coast of Africa some
singular currents prevail. Between the 30th degree of north
and the 10th degree of south latitude (the same breadth as the
westerly stream that runs into the Gulf of Mexico) an easterly
current sets in towards the shore, which has been sometimes
fatal to mariners. By this current, vessels, if they approach
too near the coast, are drawn into the Gulf of Guinea, out of
which they experience the greatest difficulty in making their
way."

Other writers speak of this current in the same manner.
One of them says, — " This current, which is known by the
name of Fernando Po, is said to be so strong as to impel
vessels powerfully towards the bay, when they happen to
come too near the coast. Its strength is such that a vessel
may, in two days, go from Maura to Rio de Benin, distant
150 leagues; and the time required to return is about six
weeks."

In this locality, the land on which the sea water rests, so far
from moving towards the east with greater velocity than the
water of that sea, most undoubtedly must move with a less
velocity, as it allows the water to proceed eastward so much
faster than itself, as to constitute that water a strong current
rurming eastward into the Gulf of Guinea. Thus on both
sides of Africa within the tropics, the oceanic currents, where
any exist, move in a direction the opposite to that which
would be found if the theory of which we are speaking were
true. There are many other currents that furnish practical
evidence of the erroneous nature of that theory ; but it is
desirable that we should in the first instance direct our
attention to those great western currents that have been
named, and to the causes which, it may be presumed, really
produce them.

In one of the extracts that have been given, some influence
is assigned to the winds that blow over the tropical seas, but
they are said to produce only a superficial effect on the body

6

ON THE CAUSES OF THE

of the water, and it is positively asserted that they do not
produce the great and deep currents of the ocean. It is neces-
sary, therefore, that we should advert to the nature of the
action of the wind, on water over which it is passing, in order
that we may see the force of this assertion. The atmosphere
presses with a weight of 15 lbs. on each square inch of the
surface of the water, and when that atmosphere is in motion
as a wind it continues to press with the same weight, and by
its friction must tend to impel the water forward in the
direction in which the wind is blowing. The immediate
effect of this wind, as is well known, is to cause a slight
ripple on the surface of the water : and afterwards in a short
time and in proportion to the velocity of the wind, to produce
small or large waves. The waves when formed present a
rougher surface for the wind to act on, and they enable it
more effectually to force the water forward in a horizontal
direction. Now this force being continued for a long time,
and acting over a large extent of surface, is, it is contended,
capable of producing a great general result, in communicating
motion to the waters of the great oceans.

It is known, too, that the gases which constitute the atmos-
phere, to a certain extent penetrate the body of any water on
which they rest; the atmosphere may therefore be con-
sidered not to press altogether on the surface of the water,
but to some extent on that portion of the gases which the
body of the water contains. Now, when the atmosphere over
the sea is put in motion and becomes a wind, it must have a
tendency to carry with it, not only all the air that is above
the surface of the water, but also that portion which has
penetrated the body of it, and that is below the surface.
How far tfeis circumstance may cause the wind more effec-
tually to carry with it the water over which it is passing may
not be known, but the tendency of a wind to produce such an
effect is sufficiently apparent.

That wind such as has been described, acting on the

GBEAT CURRElNTS OF THE OCEAN. 7

surface of water, will put it in motion and to some extent
produce a current, is so evident, that it must be and indeed is
admitted : but it is said that currents produced by this cause
are superficial, whilst the tropical currents are of great depth.
The depth of the current, however, may depend on the velocity
with which the wind blows, the constancy of its action, and
the extent of water on which it acts. When the wind first
presses on the water, it appears to act on the surface alone ;
but when that surface is put in motion, the upper water,
while in motion, presses on that which is lower, and carries it
also forward in a horizontal direction ; and this pressure
of the water while in motion is propagated to greater depths,
so long as the pressure of the wind on the surface is
continued. For the wind, moving as it does with greater
velocity than the water, exerts its force in every successive
instant of time, like gravity in the descent of bodies, and that
force is added to all the previous effect that had been pro-
duced. And over a wide ocean, there is no reason to be
assigned that the pressure of wind, acting constantly on the
surface of water, should not give motion to that water even at
great depths.

The tropical trade wind of the Pacific Ocean, in which
exists one of the great oceanic currents that have been named,
is first found moving slowly near to the Galapagos islands, in
say about 90 degrees of west longitude, where it produces but
a slight eiFect on the water of the ocean : but it continues
blowing westward, and generally with increasing velocity, over
not less than say 120 degrees of longitude, or 7,200 geogra-
phical miles; there is therefore, over this ocean, sufficient
space to permit the action of the comparatively rapid wind on
the surface of the water to press that water forward with
increasing rapidity, and to greater and greater depths, and
the current thus created, by the wind alone, may, it is con-
tended, be found to extend to great depths.

Another wind of the tropical regions, — the trade wind of

8

ON THE CAUSES OP THE

the Southern Atlantic, appears to have its origin in so remote
a part as near the western coast of Australia. From between
say 20 and 30 degrees of south latitude, wind blows from the
east across the Indian Ocean, and it apparently carries with it
the waters of the ocean, as an oceanic current sets on Mada-
gascar and the southern part of Africa. It then passes across
the Southern Atlantic, as a south-east wind, extending to the
coast of Brazil, followed throughout its course by the water of
the ocean. A part of this water, being impelled by the wind
through the Caribbean Sea and into the Gulf of Mexico, is
there accumulated and raised to a higher level, until it finds
an outlet in the channel between Florida and the island of
Cuba, along which channel it passes as the well-known Gulf
Stream. Now wind, acting constantly on the surface of water
as these trade winds do, and over the extent of two great
oceans, must, for the reasons that have been giten, be con-
sidered fully able to set that water in motion, not merely on
the surface or a little below it, but to a depth quite equal to
that at which the currents are found in the Southern Atlantic,
the Caribbean Sea, or the Gulf of Mexico.

The eastern trade wind of the Northern Atlantic in like
manner traverses the surface of the part of the ocean that lies
between the Canary Islands and the West Indies, taking
water with it, which water, in conjunction with that which
comes from the Southern Atlantic, is forced into the Gulf of
Mexico ; and the water of these two currents is, by its
accumulation and acquired velocity, carried northward to the
bank of Newfoundland, from which it is deflected across the
Atlantic.

It is evidently the same kind of force, namely, the force of
the wind acting on the surface of water, that produces the
oceanic current that has been already alluded to, in the Gulf
of Guinea, which, to the surprise of the rotatory theorists,
flows in an opposite direction to those just mentioned ! A
strong wind from the west here traverses only a moderate

\

\

GREAT CUBRENT8 OP THE OCEAN. 0

extent of sea, and blows into this gulf towards the shore ; yet
this wind, short as is its course, evidently forces the water
forward and creates the oceanic current, no other cause being
found to produce it in this case. But if wind, by blowing
over so comparatively small an extent of sea, can produce
such a rapid oceanic current as that which exists in the Gulf
of Guinea, there can be no reason given that the same agent
should not, by passing over the Pacific, the Indian, and the
Atlantic Oceans, produce strong currents in them.

It has been long observed that wind blowing over water
towards land, acts on water which is obstructed by the land,
with a force sufficient to raise it to a considerably higher level
than it would otherwise attain. This has been particularly
noticed in the river Thames, where a strong wind acting in
the same direction as the flowing tide, raises the water much
above the proper tidal elevation, whilst the wind acting in the
opposite direction to the tide produces a contrary result : the
same effects are experienced in the Severn. In the canal
between Runcorn and Manchester which has a level of con-
siderable extent, the wind, when it blows strongly from
Runcorn, raises the water above the true level at Manchester.
The same kind of effect is produced in the Forth and Clyde
Canal. When the wind has for some time blown strongly from
Suez, at the head of the Red Sea, it is said that the water of
that sea has been forced southward to so great an extent, as
to leave the bed of the sea almost fordable, though, at other
times it is deep. Mr. Taylor, the astronomer at Madras,
informs us that " the north-east monsoon sets in at that place
about the 19th of October, and along with the wind a current
sets along the shore. It reaches its maximum velocity about
the 1st of November, running then three miles an hour.
During this interval the sea, on a squally day, rises two and
a half feet above and sinks two and a half feet below its mean
level, and, in the case of a gale of wind, it may possibly reach
to double this amount." " On the 21st May 1833, a terrible

10

OK THE CAUSES OF THE

Storm raged in the Bay of Bengal near the mouth of the
Hoogly, when the tide, at the mouth of that river, rose more
than twelve feet above the ordinary height of the springs !"
These are a few of the numberless instances which might be
adduced to shew that wind, acting on the surface of confined
water, produces upon it great effect in raising its level ; but
when there is ample space for the water to move forward, the
wind readily produces a current, and it is evident from the
nature of the force that is in action, that that current will,
in deep water, extend to depths proportioned to the length of
time that the wind has acted on the water which is in motion.
There are parts, other than those which have been men-
tioned, where winds evidently create oceanic currents. One
blows from the south along the western coast of South
America, and an oceanic current is found moving with it,
increasing in velocity with the increase of the wind and carry-
ing comparatively cold water even to the equator. This
current of the ocean runs from south to north, and not from
east to west, as the so-called rotatory currents do ; the surface
of the land therefore moving easterly, faster than the water
resting on it, cannot account for this current, which must be
produced by the wind. There is another extensive current
which is thus described : — " In the Indian Ocean we find
the well known current that runs from south to north,
from the west coast of New Holland, (Australia,) and
from the Island of Sumatra, as far as the bottom of the
Gulf of Bengal." It also " impels one of its branches through
the Strait of India; thence it runs with great violence into the
Chinese Seas, and was found by La Perouse to be of great
strength in the Sea of Japan, and in the Channel of Tartary."
(p. 35, Lizars.) This great current, it appears, has to cross the
equator near Sumatra, from which part there is open sea ex-
tending say three thousand miles to the coast of Africa, and if
the water of the ocean were here left behind by the land, it
would have an apparent current westward, that is in the diree-

GEE AT CURRENTS OF THE OCEAN.

11

tion of Africa ! But we see that it runs not west but north,
into the Bay of Bengal, and then passes to the east through
the Indian and Chinese Seas. This extensive oceanic current,
therefore, which directly crosses the equator, and which, in
the Indian and- Chinese Seas, runs eastward, and therefore
rotates faster eastward than the land, cannot be water left
behind by the land.

But, it is in those parts of the world where the direction of
the oceanic currents changes with the season, that we have
the strongest proof of the errors of those writers who attri-
bute the currents to the rotatory motion of the earth. That
motion is always the same, quite independent of seasons, and
any effect really produced by it would be undisturbed by
changes in the seasons ; this would be more particularly the
case within the tropical regions, where the rotatory motion of
the surface of the earth is the most rapid. Now, over the
northern Indian Ocean, the Bay of Bengal, and the China
Sea, the south-west monsoon prevails during summer, and
the north-east monsoon blows during the winter. And the
oceanic currents of these parts of the world are found to
obey, not the rotatory motion of the earth, as they should
according to the rotatory theory, but for the time the influ-
ence of the prevailing wind, — changing regularly with the
change of the season. Thus we are told by one writer that
*' between Cochin China and Malacca, when the western
monsoon blows, that is, from April to August, the current
sets eastward against the general motion. In like manner
for some months after the middle of February the currents
set from the Maldives towards India on the east, against the
general motion of the sea. Varinius says that at Java in the
Straits of Sunda, when the monsoon blows from the west, that
is, in the month of May, the currents set to the eastward con-
trary to the general motion. Between the islands of Celebes
and Madura, when the western monsoon sets in, that is, in
December, January, and February, or when the winds blow

12

ON THE CAUSES OF THE

from the north-west or between the north and west, the
currents set to the south-east or between the south and east."
— Rees' Cyclopedia.

Davidson, in an account of his voyage in this part of the
world, says, — " From April to September the south-east
monsoon blows in Torres Straits, and the westerly monsoon
prevails during October and the five following months, and
these last winds blow so strongly as to close the passage of
those straits," (from the Pacific.) He also further states that
" the barrier reef extends from the coast of New Holland
(Australia) to that of Papua, (or New Guinea,) with numerous
gaps and entrances in it, which appear to be kept open by
the current that for six months in the year runs through
them from the Pacific to the Indian Sea, and in the contrary
direction during the other six." (p. 214.) It thus appears
that during one half of the year the wind blows from the
Pacific Ocean through these straits, and then the oceanic
current runs through them from the Pacific; but during the
other half the wind blows from the Indian Ocean, and then
the current runs with it from that ocean. If the solid land
in its rotation towards the east left the water behind, and gave
it an apparent motion towards the west, it most undoubtedly
would run westward here from the wide Pacific Ocean, in the
winter as well as in the summer, — from October to March,
as well as from March to October, — seeing that the rotatory
motion would always produce precisely the same effect. But
as it does not do so, we must conclude that it is the changing
wind that produces the currents which so uniformly change
with it.

These accounts of the alterations of the oceanic currents
with the change in the direction of the wind, are mostly given
by writers who supposed that the rotation of the earth was
the great general cause of the currents, and they speak of the
altered direction of the water in the particular cases with
surprise. There is, therefore, every reason to place confidence

GEEAT CUaRENTS OF THE OCEAN.

13

in their accounts; and their statements shew not only that
wind can produce rapid motion in the water of the ocean over
which it passes, but that it produces the motion in a short
time, and while passing over only a limited space. It is
always soon after the wind changes that the ocean current
changes, and many of the currents run with great force in a
direction exactly contrary to that which is erroneously sup-
posed to be their natural direction consequent on the rotation
of the earth. But if within these comparatively limited spaces
wind can soon put water in rapid motion, it is sufficiently
evident that the same wind acting on the surface of broad
oceans, and for a much longer time, is capable of producing
proportionately greater effect, and it may tl:erefore be ad-
mitted to be able to create the currents that are found in the
widest and deepest seas.

It has thus been found that all the great oceanic currents
that have been pointed out are accompanied by winds ; that,
although they sometimes move in accordance with the rota-
tory theory, they at other times run in opposition to it, but
they always run in the direction of the wind, and they change
as the wind changes. The evidence against the rotation theory
may therefore be said to be strong and complete, and that
theory may be considered erroneous.

As a consequence of the greater rotatory velocity of the
surface of the globe within than without the tropics, it has
long been believed that within the tropics the surface of the
earth, in its rotation, left the atmosphere behind, and thus
produced the eastern tropical trade winds. And certainly,
from the greater velocity of the air than of the water of the
sea when passing from a slower to a quicker rotating latitude,
this was not an unreasonable conjecture ; the Hadleyan theory
of winds was therefore plausible. But it has been proved that
even the air soon acquires the rotatory velocity of the portion
of the globe on which it presses, and is then just as ready to
obey local influences as if both itself and the surface were

14

ON THE CAUSES OF THE

without rotatory motion. But if air with its lightness and
elasticity thus rapidly acquires the motion of the part of
the earth on which it rests, how much more decidedly must
heavy and comparatively inelastic water do so ? Yet it is
very probable that the opinion so generally adopted, that
the tropical trade winds were caused by the earth leav-
ing the air behind it, countenanced, if it did not give
birth to the belief, that the solid earth, in its rotation,
left the waters of the ocean behind. I am not aware
of any proof having been furnished of the superior rota-
tory velocity of the bed of the ocean, as compared with
that of the water resting on it. It appears to have been
voluntarily assumed, in order to assign a cause for the great
oceanic currents, as no other adequate cause could be found.
But when it is seen that wind has sufficient power to produce,
not only the great eastern oceanic currents, but also the other
currents which run in different directions, and with great
velocities, and that wind is always in action wherever the
currents are found, such an assumption becomes unnecessary
and may be discarded.

The waters of the ocean are partially confined within basins
having bottoms unequal in depth, with sub-marine mountains
and vallies, bounded by land of irregular forms; and an ocean
current created by wind within any basin may obviously have
its direction altered by a sub-marine valley or mountain, just
as the direction of wind itself may be changed or modified in
passing through a valley above the level of the sea. And
when a force like the action of wind, in some particular
locality, raises water much above its natural level, as it
does in the Gulf of Mexico, the gravity of the water imme-
diately acts to restore the equilibrium of pressure, and may
thus produce new currents. It is not, however, the object of
this paper to pursue secondary oceanic currents through their
various courses, — that object having been only to point out
the real primary cause that puts in motion the waters whose

GREAT CURRENTS OF THE OCEAN.

16

movements constitute the great currents of the tropical
seas, which are the great currents of the ocean. And this
cause it is contended is the Wind, — which, itself produced by
condensing vapour heating the atmosphere in particular
localities, blows towards those localities, taking the water
of the ocean with it, uninfluenced to any appreciable and
palpable extent, by the rotatory motion of the surface of the
globe, — thus shewing that Wind is the real cause of the great
oceanic currents.

17

II. — Some Remarks on " The Deserted Village " of Oliver
Goldsmith. By Mr. J. Y. Caw, F.S.A., Scot.

[Read November im, 1861.]

"The Deserted Village" is a poem full of interest, from
the circumstance of the accuracy of its descriptions, and
their great fidelity, joined with its elegant and unostentatious
language. The simple scenes which it professes to describe
are so familiar, as to render the multitude qualified to judge
of the poet's correctness ; while the manner in which he
paints the characters of every-day life, draws admiration from
those whose powers of criticism have been cultivated by the
study of general literature, and whose judgment has been
matured by experience. The characters which severally
claim attention in this beautiful poem are immediately recog-
nised, and the accuracy of the poetical description is clearly
apparent.

The scene of this poem is a village which has been deserted
by its inhabitants, who have emigrated to other lands and
left the home of their fathers, formerly full of happiness and
plenty, — a place

" Where desolation saddens all the green."

The cause assigned for the change which is so pathetically
described, is the advancing luxury of the age, which, not
content with the happy population, ejects them for the
purpose of extending its parks, and enlarging its drives.

D

18

REMARKS ON " THE 0ESERTED VILLAGE

The poet takes the part of those who are suffering from
this measure of ambition, and throws into his subject much
humane feeling, mingled with honest indignation. He warms
with his subject, and hesitates not to denounce the luxury to
which he attributes the evils which he depicts, as a vice of
the blackest enormity and most dangerous quality. But
while he attacks Luxury as the depopulator of his country,
he at the same time accuses Commerce as the chief cause of
the evil. He draws the picture of a barren waste, — solitary,
without inhabitants, and without cultivation ; and having
contrasted the beauty of rural life in a happy village, with
the scene of his imagination, condemns Commerce as the
cause of the change, and in his desire to defend the peace of
rural happiness, hesitates not to accuse the enterprise of
trade as an evil which must eventually ruin the country, and
drive from it not only population but virtue. So long as he
confines himself to the delineation of the rustic population, —
to the painting their sports, habits, and occupations, — or
pictures the village church and the school or parsonage,
every one must admit the accuracy of his description and the
force of his language. But when he begins to reason as to
the causes which have operated to bring about the state of
things which he describes, his arguments appear weak and
his illustrations absurd. The beauty of the poem will com-
pensate for this failing with ordinary readers, who can
appreciate the scenes which he paints, though they will pass
over without much consideration the deductions which he
draws.

In truth, the poet would have been deficient in feeling had
he not, after lamenting the desolation, denounced the Deso-
lators ; and after he had discovered what he conceived to be
the cause of the evil, he was compelled to pour out all the
indignation of poetical justice upon the offenders. Yet when
we analyse his pathetic appeals, it will appear they are more
imaginary than real. If they were correctly stated as having

OP OLIVEB GOLDSMITH.

19

existence, then perhaps his lamentations would demand our
sympathy ; but the fallacy lies in his imagination having
invested vt'ith the power and the will of devastation and ruin,
that Commerce which the practical facts of every-day life
shew to have directly the opposite tendency. If since this
poem was published, the whole course of events in this
country goes to contradict the existence of such a scene of
desolation, the present state of Great Britain but renders
the refutation more complete. If one of the most frequently
quoted passages of the poem be examined, it will be found to
be a mixture of fallacy and truth ; nor would it be worth
while to allude to it, were it not a favourite quotation with
those who seem never to be so happy as when they are
mourning over the anticipated ruin of their country, and
predicting its speedy and irreparable downfal.

" III fares the land — to hastening ills a prey —
Where wealth accumulates, and men decay ;
Princes and lords may flourish or may fade, —
A breath can make them as a breath has made ;
But a bold peasantry, their country's pride,
When once destroyed, can never be supplied."

These lines are familiar to every one ; and all must regret
the condition of the country given over to such an evil as the
accumulation of wealth, and the diminution of the population.
But in truth, the one is incompatible with the other* The
increase of wealth is attended with an enlarged population,
which, in fact, is one great cause of the accession of riches.
Instead of villages being deserted, they grow into towns, arid
hamlets become villages under the influence of active commer-
cial industry ; while capital accumulates from the additional
activity which the energy of an increased population brings
to bear upon its creation. Nor do men decay while this is
going forward. The greater the extension of the field of
manufacturing, commercial, or mercantile industry, the greater

20

REMARKS ON " THE DESERTED VILLAGE "

the demand for all sorts of agricultural produce ; and conse-
quently, the less chance of commerce being the cause of the
decay of men, even among that part of the population which
may be termed strictly agricultural. The people in rural
districts soon increase to such a degree, as not all to be able
to find subsistence, and then migration must take place either
to some other spot in their own country, or to other lands.
Such, however, is the elasticity of population, that many may
emigrate before the country can sensibly feel their loss, so
soon do others arise to take their place. The fact of emi-
gration going forward is sometimes adduced as an evidence of
the country approaching to a state of decadence, while, if
rightly \ievved, it conveys the idea of a people increasing
from prosperity, and compelled to seek new channels for the
exertion of their industry. Commerce, instead of contri-
buting to the downfal of a country, is a powerful assistance
in mitigating the evils which naturally arise from a rapid
increase of population, as it aifords to many occupation both
at home and abroad, — binds colonies to the native country,
and, preserving alive the patriotic feeling, assuages the pain
which emigrants may feel upon leaving their homes and
setting forth for the purpose of pitching their habitation in a
far distant land.

But this forsaking of the country for the town, or of one
country for another, is not a depopulating process to be
lamented and mourned over, as if ruin were to be the
inevitable consequence. We have only to look around us to
see the effects of a population gathered from other districts of
the country, employed in actively accumulating wealth,
without any decay of men ; being, besides, the consumers of
agricultural produce to such an extent, as to render the rural
districts more populous and pi'osperous than ever they were
known to be before. The " bold peasantry," in spite of the
predictions of orators, have not yet been destroyed. They
live on in spite of the lamentations which are periodically

OF lOLIVES GOLDSMITH.

21

made as to their extinction. Doubtless the lines which we
have pointed out, as containing a mixture of truth and error,
mixed up in strange confusion, are correct in so far tliat,
when once the peasantry is destroyed, it cannot again be
supplied ; but there is not much fear of that event taking
place in our own happy country.

Nor is our poet more fortunate as he proceeds : —

*' A time there was, ere England's griefs began,
When every rood of ground maintained its man."

With poetic licence, we are informed that there was once a
time when happiness prevailed, and when the evils of
humanity were unknown ; — a golden age, when pain and
misery were not the torments of the human race, which
experience too bitterly assures us they now are. The ancient
poets held the same notion : they all lived in degenerate days,
and have, in consequence, looked back upon a period which
history assures us never existed, which they have employed
their art to describe with elegance, and which they have
clothed with the attributes of tranquillity and abundance.
The Greek and Latin Poets mixed up with this period of
primeval bliss, the Mythology which they dignified with the
beauty of their verse, and the glimpses of truth encompassed
with error which had been traditionally handed down from
generation to generation. The English Poet does not carry
his imagination so far back, but refers to a time when Eng-
land had not experienced those griefs which have in later
days, according to poetic accounts, rendered her but a
melancholy ruin of what she formerly was.

If we seek for this time of happiness and bliss, we shall
have some difficulty in finding it. We cannot expect to
discover it among the inhabitants of Britain, when Caesar
found them painted as much for warmth as ornament ; nor
among their immediate successors, subdued by the Roman
arms. Nor does it appear amidst the turbulent invasions of

22

EEMABKS ON " THE DESERTED VILLAGE

Danes, Saxons, and Normans ; nor in the contest which was
perpetually carried on between Saxons and Normans after
the Norman Conquest. Nor do we find the high and palmy
days of Feudalism and Chivalry more likely to answer the
poet's imagination, when instead of each man being main-
tained by himself, he formed part of the retinue of the baron,
whose vassal he was, and whom he was bound to follow and
to serve. Nor do the wars of the Roses, the contests of the
Stuarts, or the disturbances of the Great Rebellion, promise
more. In short, the period described cannot be found in
the chronicles of reality. Yet, perhaps the nearest approach
to this imaginary state is, after all, at the present day, when
the multiplied improvements in all branches of the Arts and
Manufactures have been diffused so abundantly, as to increase
the comforts and happiness of the great mass of the popu-
lation, and to bring within their reach enjoyments and
advantages which, at a comparatively recent date, were not
enjoyed by the nobility themselves.

If, however, the time when every rood of land maintained
its man, is not easily discovered, there are nevertheless,
visionary speculators who would, with the same false reason-
ing, endeavour to persuade the ignorant, that land being the
favourite investment for capital, it is only necessary for the
working man to purchase a small portion, and, uninstructed
in rural arts, and unaccustomed to country life, he may
expect not only to gain a subsistence, but to make himself of
some consequence in the country. This vision has had a
melancholy and complete refutation by experiment, and it is
hoped the credulity of honest but mistaken men may not
again be made the means of unprincipled adventurers robbing
them of their limited capital.

The poet describes the scene of desolation as carried to
such an extent, as to drive the inhabitants of s)veet Auburn

" to distant climes, — a dreary scene,

Where half the convex world intrudes between."

OS OLIVER GOLDSMITH.

23

But while emigrants must always experience sorrow at leaving
their own native land, and their feelings must be excited at
parting with associations which they love and respect, still, in
a country where the population keeps increasing, it is an
evidence of wisdom and prudence to remove to places where
there is a greater field for exertion. Nor is it desirable that
only the idle and dissipated should be expatriated, when they
have perhaps thrown away golden opportunities, for these are
little likely to do credit to their country, or to gain advantage
for themselves in distant places. But the prudent and indus-
trious may frequently, when their facilities at home are
limited, advantageously go abroad, and carry with them
Civilization and Arts to places where they may be enabled to
develop abilities which here must have lain dormant. And
to this very emigration does this country owe much of its
greatness. For the sending forth of her sons and her
daughters to her colonial possessions, has opened up new
channels for commerce, and new markets for manufactures ;
while a healthy and vigorous population has been reared, who
are alive to the comforts, the conveniences, and the elegancies
of civilized existence; and the condition of all parties has
been improved by the operation.

These remarks are to be understood generally : there are and
always must be exceptions. The constitution of society is such
as to furnish anomalies, — to present us with want in the midst
of plenty, and with sorrow while all around is rejoicing. Yet,
on the whole, the advantage is on the side of active exertion ;
and many of the calamities of life are caused by supiueness, or
brought on by indolence, and its consequence, dissipation.
For these there seems to be no effectual or absolute cure.
But one thing is certain, that the patient industry which feels
a want of adequate remuneration in one country, is generally
possessed of sufficient strength of mind to betake itself to
another, where it may meet with the due reward of its
exertions.

2all BEMAKKS ON " THE DESERTED VILLAGE "

It may here be noticed, that all the woes and evils of life
have always been embraced by the poets as subjects congenial
to their art. The personal experience of the individual men
may perhaps account for that acute sympathy which they
always display for the wretched and unfortunate. The diffi-
culties of the young aspirant for poetic fame, may frequently
enlist his feelings on the side of the oppressed. The kindly
disposition of the poetic race is a marked characteristic.
Indeed, the generous and noble sentiments prevail among
them, not only in the choice of subjects, but in their manner
of treating them. Hence they are generally the friends of
freedom, the advocates of liberty, the denouncers of des-
potism, the approvers of constancy in love, and the admirers
of bravery in the fight. From these circumstances, the
volumes of the poets are always favourites with the more
enlightened part of mankind, as well as with those who boast
of little knowledge but that of the modest train of the duties
of every-day life. Goldsmith, while he has elegance of
language, possesses a pathos of description which renders his
poetry agreeable to all classes. Few poems are so well
known as " The Deserted Village," and few more deservedly
appreciated. The taste of the most cultivated is pleased with
the poem, while the very school-boy is taught extracts from
it which he never forgets, and which he admires the longer
he knows them. This is a great tribute to the author, who
seems to have erected a monument of fame more durable
than the marble, and more lasting than the time-defying
brass.

The nature of this poem precludes many of the higher
branches of the poetic art, yet it is not the less pleasing to a
general reader. Descriptive poetry attempts nothing that is
grand, but clothes with elegance of language those objects
which it embraces. In this poem, in particular, no redun-
dancy of language appears, no repetition which pains the
understanding ; and so closely is it written, that almost all the

OF OLIVEB GOLDSMITH.

25

descriptions would appear inadequate by the omission of a
single line.

Take, for example, the lines which bring before us the
evening scene in the village, endeared to the memory of the
poet, before the change he deplores had passed upon it, and we
shall perceive the beauty and adaptation of his language : —

" Sweet was the sound when oft at evening's close,
Up yonder hill the village murmur rose ;
There as I passed with careless steps, and slow,
The mingled notes came softened from below ; —
The swain responsive as the milkmaid sung,
The sober herd that lowed to meet their young ;
The noisy geese that gabbled o'er the pool.
The playful children just let loose from school ;
The watch-dog's voice that bayed the whispering wind,
, And the loud laugh that spoke the vacant mind ; —

These all, in sweet confusion, sought the shade.
And filled each pause the nightingale had made."

These lines are pleasing, because they are natural. The
every-day occurrences of rural life, incidents trivial in them-
selves, yet placed together, delight on account of their being
the description of what every one can realise; — evening
passing away, — the sun going down, and universal nature
preparing for repose, — the poet's irregular walk, full per-
chance of pleasure in listening to the sounds he describes, —
the mingling notes falling upon his ear without an effort, and
the transition which follows on pointing out a variety of
sounds softened by distance, and then the idea connected with
each cause of sound, some one or other of the objects which
formerly rendered Auburn the loveliest village in the plain.

" The swain responsive as the milkmaid sung."

Here is, in one line, pointed out one of the hardy villagers —
strong, active, handsome, and laborious — relaxing from the

26 REMARKS ON " THE DESERTED TILLAGE "

labours of the day in simple strains, and accompanied by one
of the softer sex, who, delighted with the attentions of her
rustic lover, sings with a light heart a cheerful song,
awakening a response from him ; and thus, in true rural
simplicity, artlessly entwining the affections of her lover.
Around them, in the field, are the " sober herd," displaying
the characteristic fondness of the dumb creation for their
offspring; while the "noisy geese" are amusing themselves in
the pool, their distracting cackle softened by the sweeter
sounds around ; while the " playful children " keep before us
the idea of a contented and happy population, with which
the poem commenced, which is still strengthened by the
" loud laugh " which comes from among a crowd of villagers,
and the "watch-dog's bark," who has no more substantial
object of pursuit than the murmuring breeze. All these,
in sweet confusion, are said to " fill the pause the nightingale
had made." This brings us back to the poet, who, listening to
the sounds, has only done so during the intervals of the sweet
song of nature, of which true poets are always ardent admirers.
This scene was one which gave Auburn much of its interest
in the poet's afiections, and accordingly he goes on to contrast
the present state of " The Deserted Village" with its former
condition. All these have now passed away, and the Muse
sings in melancholy strains the unpropitious change. The
" cheerful murmurs" of a happy and contented population no
longer " fluctuate in the gale ;" — the footpath, overgrown with
grass, is no longer trod by the busy steps which proved the
existence of the "blooming flush of life," the absence of
which is so pathetically deplored ; and but one solitary inha-
bitant is represented as deriving a miserable subsistence by
stripping the " brook with mantling cresses spread."

The picture drawn of the modest mansion of the village
preacher is but an introduction to describe the minister him-
self. Chaucer has, among the characters in the Canterbury
Tales, a " poure persone of a toun," whose life is described

OP OLIVER GOLDSMITg.

27

with his usual quaintness and accuracy, and who is pointed
out as a model. Goldsmith's village clergyman is much more
fully pourtrayed, and in a different style. Indeed, though
both have distinctly brought forward a character familiar to
all, yet there is no such similitude existing as to lead to the
idea of any plagiarism. That they have expressed the same
notions in one or two instances was certainly to be expected,
and hence we find Chaucer saying —

" To drawen folk to heaven with fairenesse,
By good example was his besinesse ;"

while Goldsmith, amplifying his subject, conveys the same
idea with a beautiful comparison —

" And as a bird each fond endearment tries,
To tempt its new-fiedged ofispring to the skies ;
He tried each art, reproved each dull delay,
Allured to brighter worlds, and led the way."

It is unnecessary to adduce any further coincidence between
these two celebrated passages. Our poet has, with a minute-
ness which never distresses, and an exactness and accuracy
which please the more the poem is examined, completed his
portrait of one of the principal characters of the village, with
one of the most beautiful similes of which the English
language can boast: —

" As some tall cliff that lifts its awful form,
Swells from the vale and midway leaves the storm ;
Though round its breast the rolling clouds are spread.
Eternal sunshine settles on its head."

Another poet of a subsequent age has taken the same subject
in hand. Cowper, in his Task, has described a preacher, but
his manner is so full of caustic satire, directed against those
whom he should not imitate, and against practices that he

28

REMARKS ON " THE DESERTED VILLAGE

should not follow, that he has failed to convey to the minds
of his readers the very ideas which he labours to impress.
The severity of his tone takes from the beauty of his verse,
whilst the excellencies of the character are made more to
consist in his oratory, than, as the case is with Goldsmith, in
the quiet, unpretending excellency of his life. Cowper
depicts a popular speaker ; G oldsmith a good man, endeared
to those around him by the excellence of his conduct, the
kindness of his manner, and the disinterestedness of his bene-
volence, more than by the fervour of his eloquence or the
purity of his precepts. Cowper shews us the man who can
address himself with eifect to an educated congregation ;
Goldsmith the unsophisticated being whom

"E'en children followed with endearing wile,
And plucked his gown ;"

and yet, beloved as he was by all classes of the community,
"All his serious thoughts had rest in Heaven."

Dryden has attempted the same theme and at greater length ;
he has, in fact, amplified Chaucer, and presented the ancient
poet's description in more modern language.

The next character brought before us is the village school-
master, who, if not so important as the last, is not the less
useful. Those points in his character which tend to excite a
smile are the necessary consequence of the position of such
a person, whose acquirements are always superior to those
by whom he is surrounded, a circumstance which tends to
encourage a degree of self-confidence which enables him,
though vanquished in argument, still to argue. This and
much more may willingly be conceded to him who has such
an arduous daily labour as that of governing a school of
unruly boys. The schoolmaster has frequently a difficult
task to pursue between his duty to the pupils and the foolish
fondness of ignorant parents ; and if such persons are in their

OF OLIVEB GOLDSMITH.

29

fretfulness apt to exclaim against the acerbity of the teacher,
the quiet patience which the great body of those engaged in
tuition generally possess, cannot fail to be appreciated by
those who reflect upon the difficulties of their position, in a
little world where the evil passions are striving for dominion,
and which it is their constant endeavour to curb and repress.
There must be many an anxious thought when admonitions
are disregarded, and instruction neglected ; but on the other
hand, assiduity is rewarded by perceiving those who have
been well trained adorning their station in society, whatever
that may be, by fulfilling their duty in a manner creditable
to them and to their instructors.

The village master is said by the poet to be "skilled to
rule," "severe," and "stern to view;" and justly so under
the circumstances, "for every truant knew" his severity was
against those who neglected their duty, and avoided his
instructions, for he afterwards is desl^ibed as being kind,
his love to learning being the apology for his exercising
discipline upon offenders. The inhabitants treated him with
due respect, and their astonishment appears naturally and
accurately expressed, when, not being able to understand his
words of learned length, they yielded to him such homage as
was due, and wondered

" That one small head could carry all he knew ! "

The parting scene, where the inhabitants are supposed to
be about to leave their native place for the Western World,
deserves particular attention. The poet has here, in accord-
ance with the tone which runs through the poem, painted the
grief which was experienced on leaving a place which they
all loved, while the uncertainty of their future fate heightens
the mournful scene. There is here no eifort to create
effect : the language is plain, and the beauty of the descrip-
tion is its complete fidelity to nature. It may naturally
be supposed that whatever motives might lead to the deter-

30

REMAEKS ON " THE DESERTED VILLAGE

mination of a family to leave their native land, still, when
the time arrived for their departure, the feelings embodied
in the poem would most naturally arise. At that eventful
moment the hopes and expectations of a distant voyage
would vanish, before the reality of the last look upon a
home of former happiness. Ambition would for a moment
be subdued by patriotism, and even avarice would spare a
tear on the mournful occasion. Few scenes can be supposed
to be more affecting than such a departure. The young man
may set forth in the vigour of youth to push his fortune in
far distant countries, but there lurks in his tears at parting a
bright hope of a future return, which gilds his prospects, as
the rainbow, spread over the broad arch of heaven, adorns the
darkness of a clouded sky, and is the earnest of a serene and
peaceful evening. The daughter wedded to a faithful lover,
embarking for distant lands, has a prop whereon to lean the
weaknesses which in%ht otherwise overpower her, and the
hope perchance of sending her offspring homewards, as
pledges of her own expected return ; while parents thus
separated from their children, indulge the fond hope of a
future meeting, and are cheered by the possibility of their
lives being prolonged, and circumstances permitting that
pleasing reunion ; but when, in one band, the aged and infirm,
the man in the prime of his vigour, and the little babe of
yesterday, all leave the beloved home together, there is a
pang of bitterness at the last moments of their existence
spent in their native place, which few can attempt to describe,
although with the poem before us few can avoid conceiving.

" The good old sire the first prepared to go
To new-found worlds, and wept for others' woe ;
But for himself, in conscious virtue brave.
He only wished for worlds beyond the grave.
His lovely daughter, lovelier in her tears,
The fond companion of his helpless years,

OF OLIVER GOLDSMITH.

Silent, went next, neglectful of her charms.
And left a lover's for a father's arms.
With tender plaints the mother spoke her woes,
And blessed the cot where every pleasure rose ;
And kissed her thoughtless babes with many a tear,
And clasped them close, in sorrow doubly dear ;
Whilst her fond husband strove to send relief
In all the silent manliness of grief."

31

33

III. — A new Discussion of the General Equation of Curves
of the Second Degree.

By Mr. Robert Finlay, Professor of Mathematics,
New College, Manchester.

[Read December 2nd, 1851.]

The method of representing the position of a point in a plane
is the fundamental principle of the Cartesian Geometry.
To understand this method, let Ox and Oy (Fig. 1) be two
straight lines cutting each other in O, and P any point in the
same plane. Draw PQ and PR parallel to Ox and Oy;
then, if the lengths of PQ and PR be given, the position of
P in reference to Ox and Oy may be considered as known.
Hence PQ. and PR are called the co-ordinates of P, and they
are denoted respectively by x and y. The lines Ox and Oy
are called the axes of co-ordinates, and are always either
given or assumed. The point O is called the origin of
co-ordinates.

If this method of determining the position of a point be
viewed in connexion with the well known algebraical fact,
that any equation containing two variables, such as

2 x"" + S xy = 5,
can be satisfied in an infinite number of ways, by assigning
particular values to x and corresponding ones to y, it will
readily appear that any algebraical equation containing two

F

S4t

ON THE GENERAL EQUATION OF CURVES

variables can represent an infinite number of points ; and it is
easy to show that all these points lie in a certain curve, which
is called the locus of the equation. Conversely, it is evident
that every regular curve must have an equation, and by means
of this equation any question relative to the properties of the
curve may readily be reduced to algebraic form. Thus, by
means of the simple conception of Descartes, the science of
geometry was brought within the range of algebraic analysis,
and it acquired instantaneously a generality and power which
had not been imparted to it by the united efforts of many of
the greatest men of antiquity.

From the statement which I have just made relative to the
first principle of the Cartesian Geometry, it will be perceived,
that, in that system, the investigation of the properties of any
curve depends on the discussion of the equation to the curve.
When the equation is of the second degree, its discussion can
be effected without much difficulty, and in a tolerably com-
plete form. The numerous papers on this subject, however,
which have appeared from time to time, and some of which
are of very recent date, prove sufficiently that the present
mode of discussing the equation of the second degree is not
altogether satisfactory ; and this constitutes the most obvious
apology which I can offer for introducing to this Society a
subject so well known to mathematicians of every degree of
attainment.

The common method of discussing the general equation of
the second degree consists mainly in a process called the
transformation of co-ordinates. The co-ordinates of a point
may be changed in two distinct ways. 1st. By simply
changing the origin, the axes remaining parallel to their
original directions. 2nd. By turning the axes about the
origin into any new positions. The known formulas for the
former transformation are so simple and natural that nothing
further on that point can be desired. Those for the latter,
on the contrary, are exceedingly complicated ; and they have

n^^mS

I

^Fry /.J

^P

2t

fFf^J-,,

C

^

I

. I

I

io

A-

A

^.

Pr I--- h-^p,

P?

fi^ 6'/

^h

o ^::

p

\A

OF THE SECOND DEGREE.

36

the disadvantage of introducing such a multitude of trigono-
metrical symbols as to give the whole discussion the appear-
ance of a chapter on trigonometry.

In the method vphich I propose to substitute for this latter
transformation, the science is made to depend on its own
resources and notations, with little or no reference either to
the theorems or symbols of trigonometry. Another important
advantage of the method which I propose is, that the investi-
gations relative to oblique axes are very little, if at all, more
difficult than those which relate to rectangular axes. For
the sake of brevity, I have confined myself throughout the
paper to the most general case in which the co-ordinates are
oblique.

The equation of curves of the second degree can always be
reduced to the form

A3/24-2 Bi/x + Cx^ + 2 Dy + 2 Ea; + F=o (1),

where A is a positive integer, and B, C, D, E, F may be
positive or negative integers. For, if the co-efficient of y^ be
negative, it may be made positive by changing the signs of
all the terms of the equation; and if the co-efficient of x, y,
or xy, be odd, it can be made even by multiplying the whole
equation by 2.

Let R be the distance from a given point A {xi yi) to any point
xy on the curve (1), then by the theory of the straight line

R'=(y— yi)' + (a;— a;i)* + 2 (a;— a^i) (i/—yi) cos y,
y being the angle made by the positive axes of x and y.
Again, let m be the direction index of the straight line R ; then

y—y\=in {x—x^ (2),

and in virtue of this, the preceding equation becomes

R2=:(x— ici)' (m' + 2 w cos y+1) (a).

Now since Ay^=A {y—y\f + 2 Ayi {y—y{) + Ayi\
Cx' = C {x—xiY + 2 Cx^ (x—o^i) + Cari%

36

ON THE GENERAL EQUATION OF CURVES

B^^ a;=B (y— yi) (x—xi) + Bj/i {x—xi) + Bxi (y—yi) + Bari yi,

Dy =D (y— yi) + D^i, Ex=E (a;— J7i) + Ea?i,
equation (1) may be written in the form

A (r/—yiy + 2B {y~yi) {x—xi) + C {x—xiY
+ 2 {Kyi + Bo^i + D) {y—yi) + 2 (B^i + Can + E) {x—x^)
+ Ayi^ + 2Bxiyi + Cxi^ +2'Dyi + 2 Exi + F=o,
and in virtue of equation (2) this becomes
( Aw2 + 2Bm + C) {x—xif + 2 (D'm + E') (x—xi) + F = o . . . (b) ;
where, for the sake of brevity, we assume

Ayi + Bxi + lL>='D',Byi + Cxi + E=E' (c),

Ayi^ + 2 Ba?i yi + Caii^ + 2Dyi + 2Exi + Y=¥' (d).

By eliminating x — x from equations (a) and (b), we obtain
AmH2Bm + C 2(D'm+E') p .p„_^ ,.

w2 + 2mcosy+l "^ "^/(wH^mcosy+l) "^ -O.-.^e),

the roots of which are the segments APi and APg (Fig. 2) of
the straight line (2) intercepted between the point a?iyi and the
two points in which it cuts the curve (1).

(a.) By a well-known property of quadratics, we obtain
from equation (e)

AP AP r-(^^+2mcosy+l) ,«.

Al-i. Ai^,- Am2+2Bm+C ^^^'

which evidently holds good, whether the points Pi and Pa be
real or imaginary.

(/3.) When the direction-index m of the straight line (2)
satisfies the condition

Am^-\-2 Bw-f-C=o (4),

equation (e) gives R= 2{D'mi-\<y) ^ ^ '

consequently, in this case, the straight line {2) can meet the
curve (1) in only one point.

II.

When D'ot+E'=o, the middle term of equation (e) will
vanish, and the roots of that equation will be equal with
opposite signs. Hence, in this case, A must be the middle

OF THE SECOND DEGREE.

37

point of the chord Pi Pg. Now, when m is constant, or the
chord P1P2 is parallel to a given straight line y=m x, it is
evident, from equations (c), that D'm4-E'=o is the condition
that the middle point Xi yi of the chord Pi Pg may be on the
straight line

{Ai/+Ba;+'D)m+(By+Cx+E)=o (6).

Hence we see that the line (6) is the locus of the points of
bisection of all chords of the curve (1), which are parallel to
the straight line y = m x.

The straight line (6) which bisects chords parallel to the
line^=mj7, is called a diameter of the curve (1), and any
chord (2) which is bisected by the diameter (6), is called an
ordinate to that diameter.

(a.) When the ordinates are parallel to the axis of a? we have
w=o, and equation (6) becomes

B^+Ca;+E=o (7),

which is, therefore, the equation to the diameter that bisects
chords parallel to the axis of x.

(/3.) When m= 00, equation (6) gives

Ay+Bx+'D=o (8);

this is, therefore, the equation of the diameter which bisects
chords parallel to the axis of y.

(y.) It is evident from the form of equation (6) that every
diameter of the curve (1) passes through the point of intersec-
tion of the straight lines (7) and (8.) On account of this re-
markable property the intersection of these lines is called the
centre of the curve (1.) Let xg and ^3 denote the co-ordinates
of the centre, then since the point arg yg is on each of the
straight lines (7) and (8), we shall have

Ayj+Ba?24-D=o, Byg+Carj+Erro,

from which we obtain by elimination

AE— BD CD— BE ,^ ,

^="B^=:AC ' ^^="B^-=AC ^^-^

These equations indicate a very simple method of finding the

38

ON THE GENERAL EQUATION OF CURVES

centre of a curve represented bj any given equation of the
second degree.

(d.) Since every chord of the curve (1) which passes through
its centre is an ordinate to some particular diameter, it is
evident that every chord which passes through the centre k
bisected at the centre.

(«.) If B^=AC, while BD is not equal to AE, it is evident
from equations (9) that the centre of the curve (1) passes to
infinity. In this case it is usual to say that the curve has no
centre. Hence arises a division of curves of the second degree
into two classes. 1st. The central class, characterized by the
condition B^ not equal to AC. 2nd. The non-central class,
characterized by the condition B2=AC.

{(.) By multiplying equation (6) by B, we obtain
(Am + B) By + {Wm-[-BC)x + B (D»iH-E)=o.
Now when the curve (1) belongs to the non-central class this
equation may be written in the form

(Am + B) (B3/ + C^) + B (Dm+E)=o (10),

from which we see that all the diameters of a non-central curve
of the second degree are parallel to the diameter

By-{.Cx=o (lO-)

which passes through the origin of co-ordinates.

III.

In a curve of the second degree, any diameter which is per-
pendicular to its ordinates is called an axis of the curve.
Hence if m' and m denote the direction indices of an axis and
its ordinate respectively, we shall have

l + {m + m') cosy + mm' = o (a),

y being the angle made by the positive axes of x and y. Now
(a) in the case of a non-central curve we have m'= — C : B
(by eq. 10), and therefore equation (a) becomes
B + (B?w — C) cos y — m C=o,
C cosy — B_Bcosy — A

which gives m-.

B cos y — C A cos y — B

OF THE SECOND DEGREE.

39

for the direction-index of the ordinates to the axis. Substi-
tuting this value of m in equation (10), we obtain, after slight
reductions,

{(A-fC) cos y— 2 B}(B3/ + Ca:)-|-(B D-l-C E) cos y

— (C D + B E)=o (11),

which is the equation to the axis of the curve (1) when equa-
tion (1) represents a non-central curve,

(/9.) In the case of a central curve, since m' is the direction
index of the straight line (4), we have

A m m' + B (m -j- w') + C = o ;
hence, by eliminating m by means of equation (a), we get

(A cos y— B) m' H(A— C) «i'=C cos y— B (b.)

Solving this by the common rule for quadratics, we have

^ C— A ± V { (A— CP+ 4 (B— C cos y) (B— A cos y)}
'^- 2 (A cos y— B.)

Now, since the suffix of the radical in this equation may be
written in the form,
(A.—Cf (sin2 y 4- cos^ y) -|- 4 B2— 4 B (A-j- C) cos y+4 AC cos^ y,

or {(A— C)siny}^+ {2B— (A H- C)cosy}^
it follows that the roots of equation (b) are always real; and
thus we see that every central curve of the second degree has
two axes, and cannot have more than two.

IV.

Returning to the general formula in No. II, let the point A
coincide with the centre C of the curve (1), the straight line (2)
cutting the curve in P and Q (fig. 3); then by equation (3) we
shall have

CP cQ-^"^'^'+^'^^°'y+^^ J
A r»2 -f 2 B r» + C

where F'= Ky.,^+ 2 B 2/2 3:3+ C 0-2' + 2 D 2^2 H- 2 E xj-i- F,

=:D2/2+Ea:2+F (by No. II),
and the values of x^ and y^ are given by equations (9). But
since PQ is bisected in C, we have CQ,= — CP, and the pre-
ceding equation gives

40 ON THE GENEBAL EQUATION OF CURVES

^^_ /— F"im^+ 2 m COS y-^ 1) .jg.

^^-y/ Am^+2Bm + C ^ ''

(a.) The factor m^-{-2m cos y-\-l in the numerator of the
fraction under the radical sign in this equation is always posi-
tive, since it is equal to

{m + cos yY + (sin y)^,
and consequently the numerator has the same sign as — F."
The denominator admits of the form

B\2 , AC— B^)

A{(. + f)-H

A2 ]

and therefore when B^ < AC the denominator has the same
sign as A and can never vanish. Hence, since A is supposed
to be positive, No. I., when — F' is positive the value of CP
given by eq. (12) is real and finite for all values of 7n, and the
curve (1) is an oval limited in every direction ; but when F'
is positive CP is imaginary and the equation has no locus. In
the former case the curve is called an ellipse, and thus we see
that the conditions in order that the equation (1) may repre-
sent an ellipse are that B* be less than AC and F' negative.

(^.) When B^ > AC the roots of the equation Am^ + 2 Bw
+ C=o are real. If m' and m" denote these roots it is evi-
dent from equation (12) that the lines CS and CT (Fig. 4)
whose equations are

y—y^^m' {x—x^ and y~y^—rd' [x—x^
meet the curve (1) in four points at infinity. The infinite
diameters SCS' and TCT* of a curve of the second degree are
called the asymptotes of the curve. Hence we see that for
any curve (1) of the second degree, the direction indices of
the asymptotes are the roots of the quadratic equation

Aw^ + g Bw + C=o (13).

By a well known property of quadratics,

AmH2 B»i + C=A (»»— w') (w — m").
Now when m is intermediate between ni and to", one of the
factors TO — to' and to — to" is positive and the other negative,

OF THE SECOND DEGBEE.

41

and consequently the denominator of the fraction under the
radical sign in equation (12) has the same sign as — A; but
for all other values of m the factors have like signs, and there-
fore the denominator has the same sign as + A. Hence we
see, that when F' has the same sign as A, the central radius
vector CP is real for all values of m between m' and m" and
imaginary for all others, or that the curve (1) is included
within the angles S C T and S' C T ; and that when — F' has
the same sign as A, CP is imaginary for all values of m,
between m! and iri' and real for all others, or the curve is
included in the angles S C T and S' C T. In both cases the
curve is called a hyperbola, and therefore the equation (1)
always represents a hyperbola when B'^>AC, provided that
F" be finite.

(y.) When the curve (1) belongs to the non-central class it
is called a parabola; hence (ii) the conditions in order that
the equation (1) may represent a parabola are B^= AC and BD
not equal to AE.

(8.) When C = A and B = A cos y equation (li^) becomes
CP= ^—F'TX,
and consequently when F" and A have unlike signs, the curve
(1) is a circle, but when F" and A have like signs the locus
is imaginary. Hence equation (1) will represent a circle
when C=A and B = A cos y, provided that F" be negative.

V.

We have seen (No. 1) that the equation

Aw^-1-2 Bm+C=o (a)

expresses the condition that the straight line (2) may meet
the curve (1) in only one point. Now (a) when B^ > AC the
curve is a hyperbola, and the roots of this equation are the
direction-indices of its asymptotes (iv) ; hence, if from any
point two straight lines be drawn parallel to the asymptotes of
a hyperbola, each of these lines will cut the curve in only one
point.

42

ON THE EQUATION OF CUBVE8

(/3.) When B^=AC the roots of equation (a) are equal
and the value of each is — B:A; hence, we see that the only
straight line which can be drawn from a given point so as to
cut a parabola only in one point is the diameter which passes
through the given point.

(y.) When B'^<AC the roots of (a) are imaginary; and
therefore no straight line can be drawn in the plane of an
ellipse so as to cut it in only one point.

VI.

If the straight line (2) meet the curve (1) in the points Pi
and Pj = we have seen (i.) that

_F\^» + 2OTCOSy + l)

Let Qi CI2 (Pig. 5) be a chord parallel to Pi P2, and passing
through the origin of co-ordinates O ; then, since F' becomes
F when A coincides with O, we shall have

' ' AW^ + 2Bm+C '
and by dividing the former equation by the latter we obtain
AP.AP, _F-

oa,.oQ^ ■" F ^'

Similarly, if P3P4 and Q3Q4 be another pair of parallel
chords, passing through A and O respectively, we shall have

AP3^AP^_j;;

'OQ3.OQ ~ F»
and by comparing this with the last equation we get

AP,.AP, OQ,.QQ,

AP3.AP^-OQ3.0Q^ ^^*'-

Hence if two chords 0} a curve of the second degree be drawn
intersecting each other, the rectangle contained by the seg-
ments of the one will have an invariable ratio to the rectangle
contained by the segments of the other, provided that each of
the chords always remains parallel to a given straight line.

OF THE SECOND DEOBES.

43

(a.) When the line OQ3 meets the curve (1) in only one
point, (Fig. 6.) it is evident (v.) that APg will meet it only
in one point. In this case we shall have (i.)

— ¥'\/{m] + 2m^cosy\-\) — Fv/(mj + 2wjCOSy+l)

m, being the direction index of OQ.3 or AP3. Hence if we
assume

D'»j,+E'=Dm,+E (b),

we shall have F.A.P3=F.'OQ3 ; and by comparing this with
equation (a) we get

AP,.AP, _ OQ,.OQ^

AP3 ~ OQ3

(15).

Substituting for D' and E' their values given in No. i., the
condition (b) becomes

{Am^+B)t/,+(Bm, + C)x^=:o...: (V),

and this must be combined with the equation

Aw2 +2Bwii + C = o,
which expresses the condition that OQ.3 should meet the
curve in only one point (No. i). From the latter equation
we obtain

— B+^/(B2— AC) — BHt^B'
Wj = — = — suppose,

and by substituting this in equation (b'), we get, after slight
reductions

B'{Ay, +(B+BOa?J=o (c).

Now, when B'=o this equation is satisfied independently of
Xi and ^j, and therefore when the curve (1) is a parabola the
equation (15) holds good for every possible position of the point
A; but when the curve (1) is a hyperbola, B'is finite, and the
equation (c) cannot be satisfied unless x^ and y^ fulfil the
condition.

Ay,+(B+B')^,=o.

Hence we see that, in this case, the relation (15) will not hold

44

ON THE EQUATION OF CURVES

good unless the point A he on a straight line drawn through O
parallel to one of the asymptotes, in which case the points Pj
and Q, coincide.

'3

VII.

Let us now consider the case in which the curve (1) is a
parabola. Let P, P^ (Fig. 6) be an ordinate to the diameter
AP3, then since AP^^AP^ (11), equation (15) gives
AP 2 OQ,.OQ,

hence, if AV ^=:^x, APj=y, we shall have

y'^:=p'x (16)

for the equation of the parabola referred to any diameter AQ,
and the line drawn through Q3 parallel to its ordinates, as
axes of co-ordinates.

(a.) The quantity p' evidently remains invariable for the
same diameter, and is called the parameter of that diameter.
To find a general expression for p', we have (i)

OQ, .OQ, ^F(m^+g^^cosy+I)
' * Am^+^Bw+C '

no _ — ^V {m^^+2m^ cosy+1)

— F/ (B^— 2BCcosy-|-C^) . C

= 2(BE-CD) ^ ^^"^^ ^--B •

2{ClD—BE){m^ + 2mcosy-{-\)
*'• ■^"~(A7n^+2Bm+C)-/(B^— 2BCcosy+C2)'*"^ ^*
m being the direction index of the ordinates to the diameter
AP3.

(j3.) The vertex P3 of the diameter AP3 may be determined
from the simultaneous equations (1) and (10.) Combining
these with the equation B^ = AC, we obtain, by eliminating
C and y, and then eliminating A and x,

AF— D2 , BD— AE

2(BD— AE) 2[Am+B)^
CF— E* , (BE— CD) w^

2 (BE— CD) 2(Bm+C)

.(18),

OF THE SECOND DEGREE.

45

which determine the origin of the new co-ordinates introduced
in equation (16.)

(y.) When equation (1) represents a parabola we are now
prepared to determine the elements which fix its position in
relation to the original axes of co-ordinates. The simplest
elements that can be employed for this purpose appear to be
the co-oi'dinates of its principal vertex [a, /S), the direction-
index of its axis (/*,) and its principal parameter (tt). Now, by
No. II. we have

,*=— C : B=— B : A,
and the values of tt, a, jS will be obtained from the last three
equations by taking

C cos y B B cos y A . .

i5 cos y — C A cos y — B

Thus, after some easy reductions, we get

_2 (A4E— C*D) sin* y

.(19),

(A+C— 2B cos y)f *

AF— Pg BD— AE/ B— A cosy \ « \

g(BD— AE)"*" ^A2 \A+C— 2Bcosyy I
CF— E^ BE— CD/ B— Ccosy y\"'^ ''

2 (BE— CD) + 2C' \A+C— 2Bcosy/ J

VIII.

It is evident from No. ii. that the equations

(A3/ + Ba:+D)m+(B2/+Ca:+E)=o (a),

(A2/ + Bar+D)w'+B3/ + Ca;+E=o (b),

denote the diameters of the curve (1) which bisect chords
parallel to the straight lines y =^ mf x and y ^ m x respec-
tively. Now the condition that the diameter (b) should be
parallel to the straight line y = mxis

Kmm-\-^{m-\-m')+C — o (21)

and this is also the condition that the diameter (a) should
be parallel to ^ = m'x; hence we see that if two diameters
(a) and (b) he so related that the first (a) bisects all chords
parallel to the second (b), then the second will bisect all

46

ON THE EQUATION OF CUKVES

chords parallel to the first. On account of this remarkable
property the diameters (a) and (b) are said to be conjugate
to each other when their direction-indices satisfy the con-
dition (21).

(a.) If 2a' and 26' denote the lengths of the two conjugate
diameters whose equations are (b) and (a), we shall have
(IV. 12)

'2 — — F''(^'+2mcosy + l) / X

" ~ Am2 + 2Bm-hC ^'^^'

,,, _ — F"(m'2+2m'cosy + l ,..

^ ~ Am2 + 2Bw'+C ^°^'

where m and w' are subject to the condition (21).

0.) By taking the product of eqns. (c) and (dj we get

'2 y2— F'"^ (m^+^m cosy + 1) (m'^+ 2m' cos y -f 1) . .

and by subtracting the square of the first member of equation
(21) from the denominator of the fraction in its second mem-
ber this equation becomes

,^ 7/a_F"g(m^ + 2m cos y-|-l) (m"--h2m' cos y+\)
** {AC—B^)[m'—mf

Again, if S denote the inclination of the conjugate diameters
Caf &nd (bj, we obtain, by the theory of the straight line,
. 5 » {m' — mf sin^ y

sin o:zr - - ' •

[m'^+2m cos y-f- 1) [m'^+2m' cos y+ 1) '

hence, by taking the product of the last two equations, we

have

a'2 b'^ sin'»8=F".2 sin" y : (AC— B'^),

or a' b' sin S=F"sin y (AC— B'*)"* (22).

The second member of this equation is real or imaginary ac-
cording as B* is less or greater than AC ; hence when the
curve {\)is an ellipse any two conjugate semidiameters are both
real, but when it is a hyperbola, of any two conjugate semi-
diameters one is always real and the other imaginary.

(y.) Since a\ b'. sin 8 denotes the area of a parallelogram
having two adjacent sides equal to o', b\ and the contained
angle equal to S, it follows from equation (22) that the area of

OP THE SECOND DEGBEE. 4?

the parallelogram contained by any two conjugate semi-dia-
meters of an ellipse or hyperbola is invariable ; being equal to
V sin y (AC — B*)~* when the curve is an ellipse, and to
F" sin y (B* — AC)~~* when it is a hyperbola.

(d.) From equations (cj and (d) we readily obtain

{m^+2 m cos y+ 1) (A m"^-\-2 B m'+C)
a'^-^b"^ +(?7t'H2w^'cosy+l)(Aw''+2Bm+C) .«

— F" "A m^+'-Z B w+C) (AW2+2 B w'+C) ^ ''

Now we have just seen that the denominator of the fraction
in the second member is equal to — (B'* — AC) {m'-mf, and by
subtracting the first member of equation (21) multiplied by
2+2 w m' from the numerator, it becomes

(A+ C) {m'—mf+'2, cos y {(A m m'+ C) (m'+ w)+ 4 B w' w] ,
which in virtue of equation (21) easily reduces to

(A+C— 2 B cos y) {m'—mf.
Hence, by substituting these reduced expressions for the nu-
merator and denominator in equation (f), we obtain

a'2+6'2=F'' (A+C— 2 B cos y) (B^— AC)-i (23).

When the curve (1) is an ellipse a'* and b'^ are both positive,
but when it is a hyperbola one of them is positive and the
other negative. Hence equation (23) shows that, in an ellipse,
the sum, and in a hyperbola, the difference of the squares of
any tioo conjugate diameters is invariable.

(e.) We are now prepared to determine the lengths a' and b'
of two conjugate semi-diameters which shall contain a given
angle 8. For, since by equations (22) and (23) we have ,
a^+5^^_A+C— 2Bcosy

F' - B^— AC
a'^b'^ — sin2 y

p„a - ^B*— AC) sin* S '
it follows that if zi and Z2 denote the roots of the quadratic
equation,

(B^— AC) s"— (A+C— 2 B cos y) «— sin» y. sin-^ 8... (24),
we shall have

a'»=F''2, , 6'«=F''a2 (25).

^O ON THE EQUATION OF CURVES

iC) When two conjugate diameters are at right angles to
each other, it is evident, from the definition in No. iTi., that
each of them is an axis of the curve. Hence if a and b denote
the semi-axes of the curve (1), we shall have («),

a'=F'%, h''=F'% (26)

where «i and z^ are the roots of the equation

(B^— AC) z^— (A+ C— 2B cos y) z—siu^y=o (27).

This simple rule determines the magnitude and form of the
central curve represented by any equation of the second
degree ; and the position of the curve in reference to the
original axes of co-ordinates may be found by means of
equation (bj, No. iii.

{f}.) When ¥''=0, it is evident from equations (26) that the
semi-axes of the curve (1) are both zero; from which we see,
that, if the curve be of the elliptic species, it must vanish in
this case into a point ; but, if it be of the hyperbolic species,
it must coincide with its asymptotes. Hence, when B^< AC
and F"=o, the locus of equation (1) is a point; but when
B^>AC and F''=o, the locus breaks up into two straight
lines. This remark completes the discussion of central curves
given in No. iv.

IX.

Let ACA' and BCB' (Fig. 7 and 8) be any system of con-
jugate diameters of the curve (1), PP' any line parallel to the
latter and meeting the former in Q ; then, by the theorem in
No. IV., we shall have

PaQF : AaQA' : : BC.CB': AC.CA', or

PQi* : AQ.QA' :: BC^ : AC^ (28)

(a.) Let CA=a', CB=b', CQ=a?, QP=y/ then, if the
curve be an ellipse, we obtain from (28)

f : (a'+.T) {a'—x) ::b'^: a'^
but if it be a hyperbola we have

y:(a:+a') (a?— «')::&'': »'S*

OF THE SECOND DEGREE.

hence, after slight reductions, we get,

for the ellipse, -^ + ^ = 1 W,

49

for the hyperbola, — ^ = 1 {SO).

o ■* 0 ^

These, therefore, are the equations to the ellipse and hyper-
bola, referred to any system of conjugate diameters as axes of
co-ordinates.

O.) Taking now A as the origin of co-ordinates, let AQ=x,
Q,F—y, be the co-ordinates of P; then, for the ellipse,
equation (28) gives

f : X {%a'—x) : : h"" : a"", or

,f= ^^{2a'x-x^) (31);

a

b«t, when the curve is a hyperbola, we have

y^ : X {2a'+x) ::b'^: a'\ or

y'=^,{a2'x+x^) (32).

Equations (31) and (32) are the equations to an ellipse and
hyperbola, referred to any diameter and a line drawn through
its extremity parallel to its ordinates as axes of co-ordinates.
The values of the constants a and b' which occur in the last
four equations are given by equations (c) and (d) of No. viri.

Returning to equation (e) of No. i., it is evident that when
the co-ordinates Xi y^ of the point A satisfy; the conditions

F=o, D'm+E'=o ....(a),

each of the roots of equation (e) will be zero, and conse-
quently the straight line (2) will be a tangent to the curve (1).
The former condition, F'=:o, merely implies that the point
A should be on the curve (1). From the latter we obtain
«»= — E' : D', which substituted in equation (2) gives

^'{y-Vi )+E' ix-x, )=o (b)

for the equation of the tangent applied to the curve (1) at the
point xi yx , From equation (b) we readily deduce

u

56

ON THE EQUATION OF CURVES

or (A^i H-Bx, +D)2/+ (B^i +Ca:, +E)ar

+ Dy,+Eari + F=o (33),

which is a simpler form of the equation to the tangent applied
to the curve (1) at the point xi y^.

(a.) Tlie equation DVi-J-E'=o may also be considered as
the condition that the straight line (b) may pass through the
point Xi y\; and therefore it determines the direction-index
m of the ordinates to the diameter of the curve (1) which
passes through a given point A. Hence we see that the
tangent applied to any curve of the second degree at a point A
is parallel to the ordinates of the diameter which passes
through that point.

(^.) Let two straight lines be drawn from a fixed point Xi yy
touching the curve (1) at the points x'y' and x"y" respectively;
then, since each of these tangents passes through the point
^1 2/ 1 } we shall have, by equation (33),

{Ay' + Bx + D)2/i + W + Cx +E)«, + Dy' + Ear' + F=o,
{Ay" + Bx" + D) 2/, + (By" + Cx" + E)Xi + Dy" + Ex" + F=o.
But these are also the conditions that the points x' y' and x" y"
may be on the straight line

(Ayi + Bxi + D)2/ + (Bt/i+Cari + E)jr+D^, + Ej:,+F=o...(34);
hence it is evident that the straight line (34) is the chord of
contact of two tangents drawn to the curve (1) from the given
point X\ y\.

(y.) \i X yhe the point of intersection of any two tangents
to the curve (1), and Xiyi any fixed point in the chord of
contact, we shall have, by equation (34),
{Ay + Bx + D)3/, + {By + Cx + E)xi + Dj/ + Ex + F=o,
which can also be written in the form

(A^,+Bxi4-D)y+(B3^, + Cx, + E)x+D5^,+Ex, + F=o...(35).
Hence we see that, if any chord of the curve (1) be drawn
through the fixed point Xi yx, and tangents he applied to the
curve at its extremities, the locus of the intersection of the
tangents is the straight line (35).

OS" THE SECOND DEGREE.

51

XI.

We have seen (vi. a) that if AO be a line parallel to an
asymptote of a hyperbola, cutting the curve in P3, and the two
parallel chords Pi Pj and Qi Q2 in A and O respectively, we
shall have

APi.APa: OQ,. OQ2 : : APgiOPs.
Now, when A O coincides with an asymptote, A P3 and
O P3 become infinite, and may evidently be considered as
equal. Hence we see that, if any chord Pi Pj of a hyperbola
be drawn parallel to a given straight line, and produced if
necessary to meet an asymptote in A, the rectangle contained
by the segments into which the chord is cut by the asymptote is
invariable.

(a.) When A coincides with the centre C of the hyperbola,
the points Pi and P2 may be real or imaginary, but the rect-
angle C Pj . C P2 is real, and equal to

—E"(m^ + 2 w cosy + 1) : (Aw^ + 2Bm + C), (iv),
where m is the direction-index of Pj Pj . Hence (viii. a) the
rectangle A Pi . A P2 is equal to the square of the semi-
diameter which is parallel to Pi P2 .

(/3.) If Pi P2 be produced to meet the other asymptote in
A', we shall have (a).

AP, . AP2= A'Pi. A'Pa,
since each of these rectangles is equal to the square of the
semidiameter parallel to Pi P2. From this equation it is
evident that APi = A' P2, and thus we see that if any
straight line be drawn cutting a hyperbola and its asymptotes,
the segments intercepted between the curve and its asymptotes
shall be equal.

{y.) When the chord Pi Pa becomes a tangent, the points
Pi and Pa coalesce in a point of contact P, and APi . AP2 be-
comes equal to AP ^ . Hence (a) if any tangent be applied
to a hyperbola and produced to meet the asymptotes y the part
of the tangent intercepted between the asymptotes is equal to

52

ON THE EQUATION OF CURVES

the diameter of the hyperbola which is parallel to it, and that
portion of the tangent is bisected at the point of contact.

(5.) Since the diameter of a hyperbola which passes through
the point of contact is conjugate to the diameter which is
parallel to the tangent (X.a), it follows from the properties (y)
that the area of the triangle contained by any tangent and the
asymptotes, is equal to the area of the parallelogram contained
by the system of conjugate semidiameters one of which is
parallel to the tangent and the other passes through the point
of contact. Hence the area of the triangle in question is
the same for every tangent, and equal to

F" sin y (B2 — AC)-4, (XI. y).

(f.) If straight lines be drawn from the point of contact P
parallel to the asymptotes, the area of the parallelogram CP
formed by these lines and the asymptotes will evidently be
half the area of the triangle formed by the tangent and the
asymptotes. Hence, denoting the parallels by x and y, we
have (§)

xy sin ^ = I F^ sin y (B^ — AC),-*
where ff denotes the angle contained by the asymptotes. If^
for the sake of brevity, we assume

c* = i F'^ sin y (sin d)-^ (B^ — AC)-* (a),

the last equation becomes

xy = lc' ..(36),

which is the equation of the hyperbola referred to its asymp-
totes as axes of co-ordinates.

(f.) Let m' and m'^ denote the direction-indices of the
asymptotes, then by the theory of the straight line

tan^= ' ^^^~^j^ •

I +m m +{m +m ) cos y

Now since m' and m" are the roots of the equation

Am' + 2Bm+C=o, (iv. ^),

we shall have A {m'+ m") -\- 2 B=o, Am' m" — C=Oy

and A {m—m") = 2 / (B^ — AC) ;

OP THE SECOND DEGKEE. 53

tan.^^;V/(B^-^Q (37).

A + C — 2 B cos 7 ^ '

From this equation we readily deduce
sin 6 2 / (B2 — AC)

sin y l/ (A + C — 2 B cos yf + 4 (B^ — AC) sin V
and by substituting this in equation (a) we get

c^=jp^^/((A + C— 2Bcosy)2+4(B2— AC)sinV}(38).

The constant c, determined by this equation, is sometimes
called the power of the hyperbola.

XII.

Any point ari 3^1 being given in the plane of the curve (1),
the straight line whose equation is

( A^, + Ba;, + D)3/ + (By , + Car, + E)ar + Dy 1 + EoJi 4- F = 0 . . . (39)
is called the polar of the point ajj y\ in relation to the curve
(1), and the point Xx y\ is called the pole of the straight line
(39). From these definitions the following theorems are
immediately obvious.

(a.) When the pole is on the curve (1), the polar passes
through the pole and touches the curve at that point, (x).

(^.) When the pole is without the curve, the polar is the
chord of contact of the two tangents drawn from the pole to
the curve (x, /3).

(y.) When the pole is within the curve, the polar is the
locus of the intersection of two tangents applied to the curve
at the extremities of any chord passing through the pole.
This is also true when the pole is on the curve (1) or outside

of it (x. y).

(S.) When the pole is at the centre of the curve (1),
Kyx + Ba;, + D = o, B^/, + Ca^i + E=o, (ii, y),
and the equation of the polar becomes, (iv),

o.y + o. x + F"=o;
hence when the pole is at the centre of the curve the polar is
at infinity.

64

ON THE EQUATION OF CURVES

((.) When the pole is at the origin of co-ordinates we have
xi r= 0, yi = 0, and the equation of the polar becomes

By + Ex + F^zo (40).

(CO If the co-ordinates of the pole satisfy the equations,

B^^i + Cori + E=o, D^^, + Exi + F=o (a),

equation (39) becomes y=o, and the polar is the axis of ar.
Hence equations (a) determine the pole of the axis of x.
(>?.) If the co-ordinates of the pole satisfy the equations

A^^i + Bx, + lD=o, Dyi + Ea:, + F=o (b),

the polar is the axis of y, and therefore equations (b) deter-
mine the pole of the axis of y.

XIII.

Let X\ yi denote the co-ordinates of the pole of the
straight line

y =z mx + h (a);

then, since the polar of the point j;i yi is

(A3/1 -f Ba;, +D)^ + (By 1 +Ca;i +E);r+D3^i + Ea;i+F=o,(b),

the straight lines (a) and (b) are identical, and we have

(A^i + Bxi -f- D)m + By, -j- Cx, + E=o (41),

(Ay ,+ Ba;i + D) A + Dyi -|- Ea;i + F=o (42).

(a.) When m and h are given constants, these equations
enable us to find the pole Xi y\ of the straight line (a).

(/3.) When in is constant and h variable, equation (a) denotes
a series of lines parallel to the straight line y=7» x; and equa-
tion (41) shows that the pole of any of these lines lies on the
diameter

(Ay+Ba;+D) m4-By+Ca;-hE=o.
Hence if a system of straight lines be drawn in the plane of a
curve of the second degree parallel to a given line, the locus of
their poles is the diameter which bisects chords parallel to
that line.

(y.) Let equation (a) denote a system of straight lines pass-
ing through a given point x' y\ then
y' = m x' + h,

OF THE SECOND DEGBEE.

55

and by substituting the values of m and h given by equations
(41) and (42) this equation becomes

(Ay, + B;ri + D)/ + (B^, + Caj. + E) «' + D?/, + Ea: 1 +F=o,
which is the condition that the point x\ y\ may be on the
straight line

(A2/'+Ba:' + D) 2/+ (By' + Ca;'+E) ar4-Dt/'+Ea;'+F=o.
Hence if a system of straight lines (a) pass through a given
point (x' y' )y the locus of their poles is the polar of that
point.

(8.) Conversely, if any number of points lie on a straight
line, their polars intersect in the pole of that line.
Let the equation to the straight line be

y=^mx+h (c),

and let Xi y\ be any point on this line, so that

yi = m Xi + h (d);

then since the polar of Xi yi is, (xii),

(Ayi +Bx'i +D)y + (Byi 4-Ca;i+E)x+Dyi +Exi +F=o,
we obtain by eliminating yi,

{(At/ + Ba? + D) w + By+Ca; + E}a;i,
+ (A2/ + Ba;+D) A+Dy+Ea;+F=o.
Now when x\ y\ is any point on the straight line (c), x\ will
be indeterminate, and the last equation shows that the polar
of any point on the straight line (c) must pass through the
intersection of the straight lines

(Ay+Ba;+D)w+B2/ + Ca;+E=o^ ,.

(Ay+B:c+D) h +Dy+Eaj+F=o; ^^''

which, by equations (41) and (42), is the pole of the straight
line (c).

XIV.

The forms of the principal curves represented by the gene-
ral equation (1) have been investigated in No. iv., and to
complete the discussion there given we may now consider the
case in which B^ = AC, and BD=AE. Tn this case we have
BE =: CD, and the values of x-i and y% given by equations

56

ON THE EQUATION OF CURVES

(9) assume the indeterminate form §. Multiplying equation
(7) by B we obtain

B2 3^+BCb+ BE = o,
and in virtue of the preceding conditions this becomes

Ay + Bx+ D = o (a);

hence equations (7) and (8) are identical in this case, and any
point in the straight line (a) may be considered as the centre
of the locus.

By multiplying equation (1) by A, we obtain, in this case,

A^y^+2ABxy+'B''x^+2A'Dy-\-2B'Dx+A'E=o,
or (Ay+Bar}2 + 2D {Ay+Bx)+AY=o,

and .-. Ay+Bx=—D±\/(D^'-A¥) (b);

hence when D^ > AF the locus is two straight lines (b) parallel
to the line (a), when D^ = AF the locus is the straight line
(a), and when D^ < AF the locus is imaginary.

The loci which can be represented by the general equation
(1) may now be enumerated as follows : —
Central Class.

(a.) If C= A, and B = A cos y, the locus is a circle (iv., 8).

(/3.) If B^ < AC and F'' < o, the locus is an ellipse (iv., a).

(y.) If B* < AC and F"=o, the locus is a point (viii., t?).

(S.) If B'^ < AC and F" > o, the locus is imaginary (iv., a).

(f.) If B^ > AC and F" not = o, the locus is a hyperbola
(IV., )3).

(C.) If B'^> AC and F''=o, the locus is two straight lines
cutting one another (viii., rj).

(r,.) If B2 = AC, BD= AE, and D^ > AF, the locus is two
parallel straight lines (xiv).

(6.) If B^ = AC, BD=AE, and D^ = AF, the locus is one
straight line (xiv).

(,.) If B* = AC, BD = AE, D^ < AF, the locus is imagi-
nary (xiv).

NONCENTRAL ClASS.

If B'^ = AC and BD not = AE, the locus is a parabola
(iv., y).

OF THE SECOND DEGREE.

57

r^ XV.

Hitherto our attention has been chiefly directed to the most
general form (1) of the equation of the second degree, but in
many cases the equation becomes simplified in form by the
evanescence of one or more of its co-efficients A, B, C, &c.
Some of the simplest of these forms have been given in Nos.
VII., IX., XI,, and we now proceed to point out a few others.

(a.) When the curve (1) passes through the origin of co-
ordinates its equation must be satisfied by the simultaneous
equations x=o and t/=o; hence we shall have F=o, and
equation (1) takes the form

Af + 2Bxy+ Cx^ + 2D2/ + 2Ex-o (a).

(^.) When E=o the diameter (7) which bisects chords
parallel to the axis of x passes through the origin ; hence
when the origin is on the diameter which bisects chords
parallel to the axis of a; equation (1) takes the form

A^^ + 2Bxy+Cx^ 4- 2I>y + Y=o (b).

Similarly, when the origin is on the diameter which bisects
chords parallel to the axis of y, equation (1) becomes

Af + 2Bxij+ Ca?2 + 2 Ecc + r=o (c).

When the origin is at the centre we have D=o, E=o, and
the equation becomes

Af -{- 2 Bxy + Cx^ + F=o (d).

(y.) When B=o equations (7) and (8) become
Cx-\-'E=o and Ay-{-D=o,
and therefore the diameters which bisect chords parallel to
the axes of x and y are respectively parallel to the axes of y
and X. Hence, when the axes are parallel to a system of
conjugate diameters, equation (1) takes the form

Ay^-{-Ca^ + 2I>y-t2 Ea?-i- ¥=o (e).

When the curve (1) is a parabola the condition B=o gives
A=o or C=o.

(8.) When C=o equation (13) gives m=^o, and therefore
the curve (1) has an asymptote parallel to the axis of x.

I

68

ON THE EQUATION OF CURVES, ETC.

Hence, when the axis of x is parallel to an asymptote,
equation (1) becomes

A/ + 2Bxy + ^T>y + 2EiP+ F=o (f).

Similarly, when the axis of y is parallel to an asymptote, the
equation takes the form

^Bxy+Cx" +2Dy + 2Ea; + F=o (g),

and when both the axes are parallel to the asymptotes, the
equation becomes

2 Ba;y + 2 Dy + 2 I> + F=o (h).

59

IV. — On the Origin and Nature of the Forces that produce
Storms. By Mr. Alderman Hopkins.

iRead December 16^ 1851.]

Storms are strong winds, diiFering in degree and not in
nature, from ordinary winds or moderate breezes. All the
great movements of the atmosphere have their origin in
vertical currents which are produced by certain known
causes. These currents are fed from less or greater dis-
tances by horizontal currents, which press and flow towards
the area of ascent, and the horizontal currents, whether
they appear as moderate winds or storms, are thus pro-
duced by the ascending currents. These latter currents
are created by the aqueous vapour which is intermixed with
the gases of the atmosphere, heating these gases, through
the process of condensation, thus causing them to expand into
a larger space, and to press with less weight than they had
previously done on the surface of the earth. The adjoining
colder, and therefore heavier atmospheric gases then rush
under and force the warmer and lighter to ascend in the form
of vertical currents, and the heavier gases, being themselves
successively heated by the condensation of their vapour, also
rise, when more air presses towards the ascending mass, and
thus, these processes being repeated and continued, a Wind
or a Storm may be produced.

But it has been said by persons who object to the hypo-
thesis here advanced, that the heat liberated in the atmosphere
by the condensation of aqueous vapour, is not sufficient to

60

ON THE ORIGIN AND NATURE OF

lighten the air in the locality, to an extent that shall create a
rapidly ascending current. That much latent heat is however
really given out and made sensible, raising the temperature in
the part where vapour is converted into water, is well known
and universally admitted. It is familiarly experienced when
steam is condensed in our steam engines, and I have explained
it more fully in papers formerly read to this Society.

It is not however often that the whole of the vapour that is
in the atmosphere is condensed into water, or even so much
of it as there commonly is in the condensor of the steam
engine, seeing that the heat liberated in the atmosphere
warms the part and the air that is in it, and thus stops or
checks the condensation that is taking place. And it is not
until the gases are made lighter through being warmed, and
that the remaining vapour which is mingled with them is
carried successively to greater elevatians, tliat the whole or
nearly the whole of the vapour existing in any locality i»
condensed.

When dry air, that is, air entirely without vapour, is taken
to a height of, say one hundred yards, the expansion that is
consequent on the diminished incumbent pressure at that
height, cools it say 1° Fahrenheit ; but if the air be satu-
rated with vapour, some portion of the vapour will be con-
densed by the cold produced through expansion of the air,
and the result will be that the mixed mass of air and vapour
will be found to be cooled, not to the full degree of dry air
belonging to the elevation, but only to about one half of it;
the warming influence of condensation of a part of the vapour
having counteracted the cooling effect of expansion of the
gases, to the extent of the other half. The mixed mass being
however half a degree warmer than the adjoining cold air, is
forced up in the atmospheric space by the colder and heavier
air. On reaching the height of two hundred yards, incum-
bent atmospheric pressure is sufficiently reduced to cool pure
fdv 2°, but condensation of vapour counteracts this cooling to

THtS FORCES THAT PROBtJCE STOBMS.

61

the extent of one half, as just explained, and the result is
that the actual cooling of the mixed mass is only 1° instead
of 2°. This double process being continued to greater heights
in the atmosphere, the absolute cooling of the ascending mass
is only half a degree for every hundred yards of height.

The facts here stated may be proved by pumping out air that
has been deprived of vapour from the receiver of an air pump,
until expansion of the air within takes place to an extent equal
to that which occurs, on air being removed from the surface
of the earth to the height of one hundred yards in the atmos-
phere, when, as we have seen, the temperature sinks 1°. But
if the air in the receiver be saturated with vapour, some of
the vapour will be condensed by the cold of expansion, and
then the temperature of the mixture will be found to be
reduced only about half a degree. It follows from this expe-
riment that, in an atmospheric column that is ascending to
higher regions, and in which condensation of vapour is taking
place, the heat liberated reduces the cooling to about one half
of what it would otherwise be ; and two adjoining masses or
atmospheric columns of the height of, say four thousand eight
hundred yards, the one undisturbed by condensation, and the
other having condensation going on within it, would have the
temperatures as put down in the following table at the
heights named, the dew-point and temperature at the surface
of the earth being supposed to be both at 80^ : —

Yards high.

Clear air.

Clouded air.

Difference.

4,800

32°

56"

24°

4,000

40°

60°

20°

3,000

50°

65°

15°

2,000

60«

70°

10°

1,000

70°

75"

5°

0

80°

80°

0*

Now it is evident that in the part of the atmosphere which is,
say one thousand yards high, the clear air of the temperature

62

OK THE OBIGIN AND NATURE OP

of 70° and of the density and weight which belong to that
temperature, will have a tendency to press under and force
up the adjoining column that has the higher temperature of
75°, and which is therefore proportionately lighter ; and the
heavier column will press up the lighter with a force equal to
the difference in the weights of the two, which is expressed
in the numbers of the table by 5° of temperature. At the
height of two thousand yards the difference of temperature in
the two adjoining columns is 10°, and consequently the clear
air at this height will have a tendency to press up the recently
clouded air with a force expressed by the 10°. At three
thousand yards high the superior weight of the clear air is
15°, and at four thousand eight hundred yards, when the
freezing point in the clear air is reached, the difference in the
two columns is no less than 24"^. Thus we see, that on con-
densation taking place in any particular part of the atmos-
phere where the temperature and dew-point at the surface
were at 80^, it would make that part so light as to permit it
to be forced up by the adjoining heavier air at an increasing
velocity, expressed by the numbers in the table which indi-
cate the differences of the temperatures at the various heights.
The commencement of this process would be slow, like the
first movement of a railway carriage by a steam engine, but
the velocity of the ascending current would increase with the
difference of the temperatures of the two columns, until the
aqueous vapour, the material furnishing the moving power,
was exhausted. And as the velocity of the ascending cur-
rent increased, so would the quantity of air that ascended
within it increase ; and the greater that increase the larger
would be the quantity of the atmosphere that would press
from adjoining parts, to fill the comparative vacuum that had
been made by the condensation of the vapour. Here then
we see, that under the circumstances described, a very ener-
getic expanding power comes into action in the atmosphere,
which reduces the weight of the air in the locality, whilst the

tSE Forces that prodcce storms.

63

adjoining heavier air that then presses and rushes in succes-
sively to fill the comparative vacuum, must produce a hori-
zontal movement of air or a wind, the force and rapidity of
which veil! be proportioned to the degree of vacuum created.

In the table that has been given, we have exhibited the
cooling of the atmosphere through reduction of incumbent
pressures, as it may be presumed to take place in a tropical
region, to the height of only four thousand eight hundred
yards, because, in air that was undisturbed by condensation,
the temperature of 32° or the freezing point was then
attained. But there is no reason that an ascending current
heated by condensation as it proceeded, and pressed upwards
by fresh air rushing from below, should stop in its ascent
when it had reached the height of four thousand eight hun-
dred yards. On the contrary, the tendency of such a current
when supplied with sufficient vapour, which becomes lighter
through being warmed, is to permit its being raised to far
greater heights, and the difference in the temperature of the
two adjoining columns of clear and of clouded air, as long as
condensation was proceeding, would still be the measure of
power with which the heavier column would force up the
lighter. In the following table this difference is shewn up to
a height of ten thousand yards : —

Yards high.

Clear air.

Clouded air.

Difference.

10,000

—20°

30°

50°

9,000

—10°

35°

45°

8,000

0°

40°

40°

7,000

10°

45°

35°

6,000

20°

50°

30°

5,000

SO'

55°

25°

4,000

40°

60°

20°

3,000

50°

65°

15°

2,000

60°

70°

10°

1,000

70°

75°

5°

0

80°

80°

0°

64

ON THE ORIGIN AND NATURE OF

Here we see that at the height of ten thousand yards from
the surface of the earth, the difference of temperature between
the clear and the clouded atmospheric columns produced by
condensation of vapour, is no less than 50^ ; and with a
force proportioned to that difference would the former column
be disposed to press up the latter, whilst the pressure upwards
at the various intermediate heights would be as the numbers
expressing the difference of temperature.

So far we have treated of the condensation of vapour
carrying high temperature to great elevations ; but at a certain
stage of the process a new power comes into action. The
undisturbed atmosphere was presumed to be of a lower
temperature than S2°, above the height of four thousand
eight hundred yards ; any vapour, therefore, ascending above
that height and entering the cold air that existed there, would
be liable to be not only condensed into water, but to be
frozen into snow! And were it not for the heat that is
liberated by condensation, the vapour that penetrated this
lofty region would be not only condensed, but frozen. And
further, although condensation liberates much heat and keeps
the temperature in the ascending column above the freezing
point to a considerable height, yet at some greater elevation
that point will be reached even within the comparatively
warm ascending column. When this takes place and freezing
commences within the column, we have a result differing from
that which has been pointed out, as a new law then comes
into operation.

When, through reduction of incumbent pressure, the
ascending mass cools down to a temperature below 32°, the
particles of water that had been formed by condensation are
frozen ; and in freezing, the liquid water gives out the latent
heat that is always liberated when water is converted into
ice. Now this liberated heat will have a tendency to keep up
the temperature of the ascending column, and of the w^ter
and ice that are in it, and to prevent that temperature from

THE FORCES THAT PRODUCE STORMS.

65

falling below 32°. For it is well known that when a body of
water is frozen by a moderate degree of cold, the process of
freezing is slow, as the conversion of a part of the liquid into
ice liberates heat enough to preserve the remainder in the
form of water ; and it requires time for the liberated heat to
pass away before a fresh portion of the water can be frozen
by the existing degree of cold in the locality. In this way a
mixed mass of water and ice may remain a considerable time
at the temperature of 32°, in a part that is below that tem-
perature, the heat given out to the water by freezing being
nearly equal to that which is passing away ; and this compa-
ratively slow operation continues until all the water is frozen.
The same process must take place in the atmosphere, when
the particles of water produced by condensation of vapour
are frozen into snow or hail, that is into ice. As the ice is
formed the heat of liquidity of the water is set free, and the
temperature of the locality and of the substances that are in
it, is prevented sinking below 32° until all the water in the
part is frozen. It follows from this, that when an ascending
atmospheric column takes newly formed water that is within
it to a height sufficient to freeze the water, the column for
some time retains the temperature of 32°, while it is ascending
successively into colder regions. Tho respective temperatures
of the undisturbed cold air in the vicinity, and of the warmed
ascending column that is passing through it, may, under
these circumstances, be as shewn in the following table, com-
mencing from the temperature of zero at the surface ; whilst
the differences between the temperatures of the two airs
would be those which are inserted in the tabular column of
the differences: —

66

ON THE OKIGIN AND NATUBE OF

irds high.

Clear air.

Clouded air.

Difference.

10,000

—100°

32°

132°

9,000

—90°

32°

122°

8,000

—80°

32°

112°

7,000

—70°

32°

102°

6,000

—60°

32°

92°

5,000

—50°

32°

82°

4,000

—40°

32°

72°

3,000

—30°

32°

62°

2,000

—20°

32°

52°

1,000

—10°

32°

42°

0

0°

32°

32°

It will be observed that in this table we presume that in
clear and undisturbed air the temperature at the surface is at
zero, which is found only in very cold localities ; and as the
temperature is presumed to be lower after the rate of 1° for
every one hundred yards of ascent, at the height of ten
thousand yards it will be 100*^ below zero. But as we
presume that the heat liberated by condensation and freezing,
as just explained, keeps the column in which these processes
are taking place for some time at S2°, the difference between
the two columns at the full height named must be for that
time 132°. In so very cold a locality as that of which we are
now treating, we know that any vapour which escaped from
the surface of the earth and passed into the atmosphere,
would be soon condensed ; but the heat that would then be
liberated would keep the product of that condensation in a
liquid state for some certain time, however short it might be,
yet in such a part that heat would pass rapidly away, and the
liquid would be frozen. The liberated heat of liquidity
would, however, now preserve the cloud of liquid and frozen
particles for some further time at 32° ; and then two pro-
cesses, first, condensation of vapour, and secondly', congelation
of water, being successively and rapidly repeated in a column
ascending to a great height, would keep the whole mass at

THE FORCES THAT PRODUCE STORMS.

6^

32°, as long as vapour remained to be condensed and frozen.
And thus we find that the difference in the temperature of
the two adjoining parts indicated in the table, would be
established for some time, however short it might be.

It has been often observed that, when the temperature near
the surface of the earth has been greatly below the freezing
point, upon a fall of snow occurring, the temperature has
suddenly risen to 32° ; and it commonly remains there as
long as the snow continues falling. Now it is known that
this snow often descends from a considerable height in the
atmosphere, and it is to be presumed that it brings the air,
which is found to have a temperature of 32°, down with it.
The same fact is frequently observable in high latitudes, where
the cold is intense. However low the surface temperature
may have previously been, on a considerable quantity of snow
falling it shews a tendency to rise to 32°. Such changes near
the surface indicate, that in the part of the atmosphere in
which the snow was formed from floating particles of water,
whatever might be the height, the temperature in that part
could not be below SS'^*.

It is not necessary to suppose that in cold latitudes, under
the circumstances described, vapour shall be actually carried
up to so great a height as ten thousand yards, or to any other
particular height approaching it ; but what has been observed
in those latitudes gives reason to believe, that snow and
spiculae of ice are there formed from vapour at greater eleva-
tions than has been hitherto imagined. Our object at present
however is, not to shew precisely what occurs in such lofty
regions, but to explain the kind of laws that govern the
atmospheric changes that take place in them, and to point
out that to whatever extent these changes do occur, they
must be under the control of the laws that have been
exhibited.

In high latitudes, where the cold is intense, but little vapour

68

ON THE OBIGIN AND NATURE OF

is found in the atmosphere, and therefore great and extensive
atmospheric disturbances seldom take place in those parts ;
but in the tropical regions, where vapour is more abundant,
the phenomena that have been under consideration are often
exhibited in energetic action over a wide extent. It is
probably at an elevation that gives a temperature below the
freezing point, even in the warmed ascending currents, that
the fierce storms of the tropics generally take place ; and where
those storms are very violent in their character, the probability
is that condensation of vapour and freezing of water are suc-
cessively carried to a great height in the atmosphere, although
the commencement of the former of these processes may have
been in the middle, or even in the lower regions. With a
temperature and dew-point of SC^ at the surface, in an undis-
turbed atmosphere, we have seen that the freezing point is
reached at a height of four thousand eight hundred yards ; but
in a fierce tropical storm the vapour from the lower regions
may be carried very far above that height. The comparative
vacuum formed by a heated ascending current, vyhich had a
dew-point of 80*^ at the surface, and which is successively
supplied from below with equally saturated air, may produce
an ascent of not merely four thousand eight hundred yards,
but of ten thousand yards or more. And in portions of the
column the current must be rapid as well as continuous, taking
a large amount of vapour from the lower to the higher regions,
where its congelation as well as its condensation may finally
produce those great differences of temperature in adjoining
parts of the atmosphere that have been pointed out.

It is obvious that an ascending column extending over a
considerable area, or in other words, having a large horizontal
diameter, being lighter than contiguous undisturbed air, will
press with proportionately less weight on the surface of the
earth on which it rests ; and a barometer placed in such a part,
would, by the falling of the mercury, measure the diminution

THE FOBCES THAT PRODUCE STORMS. 69

of pressure. The degree, however, of that diminution in any
particular part, will depend not solely on the amount of vapour
condensed, and consequently of air heated, but also on the
height in the atmosphere at which these changes take place*
With a given amount of vapour condensed, the nearer to the
earth that the condensation occurs, the greater will be the
reduction of pressure on any particular point of its surface,
and the farther from the earth, the less the reduction of pres-
sure on any particular part. Hence it follows that in the
polar regions, where the cold of the surfjice is intense, conden-
sation of a small quantity of vapour produces a greater effect
on the mercury of the barometer than it does in the warm
tropical regions. In the latter regions the base of the column
of warmed air may be at a considerable height, and the total
reduced pressure of that base may be spread over a large area
of the surface of the earth, and may consequently affect each
particular part of that surface in but a small degree : whilst in
the former regions the base of the warm column may be close
to the earth, and the reduction of pressure may therefore be
limited to a small area, within which however the pressure
might be greatly reduced*

Air is expanded by heat, say a 480th part of its bulk, for
every increase of 1° of temperature, and consequently it will
be expanded one-tenth part by an increase of 48° of tempe-
rature. It follows therefore that where an ascending mixed
mass of air and vapour reaches a mean temperature of 48°,
above that of the undisturbed part at the same elevation, the
ascending mass would be one-tenth lighter than the adjoining
part, a difference equal to the weight of three inches of mer-
cury, and sufficient to cause the heavier to press up the lighter
air with great force. On the whole it is contended, that if an
adequate portion of aqueous vapour be supplied to any ascend-
ing mass of the atmosphere, the laws of cooling of the gases
by expansion, and of heating them through condensation and

70

FORCES THAT PEODUCE ST0EM8

congelation of vapours, that are known to exist, when traced
in their operations extending into the higher parts of the
atmosphere, are capable of producing disturbances of a very
energetic character, such as those attending hail and thunder
storms. And it is submitted, that the causes which have been
here traced are fully adequate to the production of all the
* effects that are experienced in strong winds or fierce storms.

71

V. — Contributions to the Knowledge of the Manufacture

of Gas.

By B. Frankland, Ph.D., F.C.S., Professor of Chemistry
at Owens College.

The importance of the manufacture of gas for illuminating
purposes must be admitted by all, and artificial light thus
procured has become almost a necessary of life ; yet it is
remarkable how little progress has been made in this branch
of art, since the first few years of its existence. It is true that
so far as the mechanical part of the process is concerned,
considerable improvements have been effected, and by the
application of new methods of purification, we are now
enabled to free the gas from almost every objectionable
ingredient, yet, although the generation of luminiferous gas
depends essentially upon chemical principles, as it is the
modification of the force of affinity by the agency of heat
that determines the products of every destructive distillation,
it is impossible carefully to peruse the results of the late Dr.
Henry's beautiful and elaborate researches on this subject,
without being forcibly struck by the comparatively slight
advance which has been made in what I may be allowed to
call the generating department of gas-making, since that
distinguished philosopher applied himself to its investigation.
Better descriptions of coal and some new materials have been
tried and have come into use ; the disengagement of the gas
has been facilitated by decreasing the pressure within the
retorts ; and attempts have been made to increase the propor-
tion of luminiferous ingredients, by regulating the heat so as

72

CONTRIBUTIONS TO THE KNOWLEDGE

to make it most favourable for their development; but no
new principle has been applied to the generating process, and
although the attempts above alluded to have been attended
with some success, yet it is evident from Dr. Henry's descrip-
tion of the quantity and quality of gases obtained from
coal and cannel, which was laid before this society in 1819,
that little has been gained either as regards the quantity of
gas obtainable from a given weight of coal or its illuminating
power. Our knowledge of the constituents of coal gas has
also been very little extended, although our means of gaseous
investigation have been greatly increased by the labours of
Bunsen, Kolbe, Regnault and others, in perfecting the me-
thods employed in the analysis of gases.

Under these circumstances, I venture to hope that the
observations contained in the following pages, imperfect as
they are in many respects, may not be altogether unaccept-
able as contributions to our present knowledge of this very
important branch of manufactures. These observations
derive their origin from an extensive series of experiments
just concluded, which I made at the request of two merchants
of this town, upon a new process of gas manufacture known
as White's Hydrocarbon process, of which I believe the
members of this society are not entirely ignorant. In detail-
ing these experiments and the conclusions arising from them,
I shall endeavour as much as possible to eschew the commer-
cial relations of the subject, and confine myself to points of a
strictly scientific character.

The usual process of gas-making consists, as is well known,
in exposing coal or cannel to a red heat in close vessels of
convenient size and shape, until all, or the greater part of the
volatile matter is expelled. Coke is the material left in the
retort, and the matters volatilized consist of condensible
vapours, and permanent gases more or less saturated with
these vapours. It does not appear that the quantity of coke
obtained from a given weight of coal is liable to any import-

OF THE MANUFACTURE OF GAS.

73

ant increase or diminution, from any variation of temperature
between the limits that are usually employed in gas-making,
but the relative amount and also the quality of the liquid and
gaseous products, depend very considerably upon the tempe-
rature to which the materials are exposed in the retorts. As
a general rule, the lower the heat the more do the liquid
products increase at the expense of the gaseous ones ; whilst
the higher the heat the greater is the yield in gas, the
quantity of the liquids being at the same time diminished ;
but not only does the relative quantity of the gas produced
thus vary, its quality also depends essentially upon the heat
employed, that produced at low temperatures being usually
superior to that evolved at higher ones.

The gas thus generated contains several constituents which
require to be removed, before it is fit for use as a light-giving
material ; but it is not my intention at present to discuss the
methods used in the purification of gas, or indeed to describe
more minutely the usual processes of manufacture, since
these have been so fully and clearly delineated in an excellent
paper read before the society last year by Mr. Leigh ; I
therefore confine myself to some general observations upon
the relative value of the constituents of coal or other gas,
to considerations respecting the quantity and quality of the
purified gas obtainable froni the materials in general use, and
the methods by which both the one and the other may be
increased.

The constituents of purified gas are hydrogen, light carbu-
retted hydrogen, carbonic oxide, defiant and other gases,
having the general formula Cn Hn, the vapours of hydro-
carbons having the formula Cn Hn and Cn H(n— e), and
other hydrocarbons whose formulae are unknown : in addition
to these, coal gas usually contains small quantities of nitrogen,
oxygen, and bisulphuret of carbon vapour; but, for our
present purpose, these may be entirely disregarded.

It has always been maintained that hydrogen and carbonic

L

74

CONTRIBUTIONS TO THE KNOWLEDGE

oxide possess no illuminating power, and that the light emit-
ted by coal gas is due to the light carburetted hydrogen,
defiant gas, and other hydrocarbons. I hope, however, to
prove by the experiments detailed below, that, for all practical
purposes, light carburetted hydrogen is also entirely devoid
of illuminating power, and that therefore, the whole of the
light-giving effect is due to the olefiant gas and hydrocarbons.
This is an important point, as we shall find that it much
simplifies the estimation of the illuminating power of any
sample of gas, and teaches us that the nature of the combus-
tible diluents of the olefiant gas and hydrocarbons, has no
effect whatever upon the quantity of light emitted by the
mixture.

The constituents of coal and other gases may be divided
into two classes, viz., illuminating and non-illuminating con-
stituents ; to the first will belong olefiant gas and the other
hydrocarbons above mentioned, and to the second, light car-
buretted hydrogen, hydrogen and carbonic oxide. To the
first class alone the illuminating power of the gas is due, but
some member of the second class is also indispensable as a
diluent, without which we should find great difficulty in con-
suming the hydrocarbons, without the production of much
smoke and consequent loss of light. The members of the
first class are all decomposed instantaneously at a white heat,
at a red heat more slowly, depositing the whole or the greater
part of their carbon in the form of very fine particles, which
become so many centres for the radiation of light in the gas
flame, and the greater the number of particles existing in
any flame at the same moment, the greater will be the light
emitted by that flame. It is therefore evident that the value
of these hydrocarbons for the production of light, depends
directly upon the quantity of carbon contained in a given
volume, and is altogether independent of the hydrogen with
which this carbon is combined ; consequently, the densest or
most easily condensible of these gases and vapours of the first

OF THE MANUFACTURE OF GAS.

75

class, are those wliich possess the highest illuminating power.
All the compounds belonging to this class are, as before
stated, decomposed more or less rapidly at a red heat, and in
the ordinary process of gas-making, the interior walls of the
retorts soon become coated with a stratum of carbon derived
from this source. Now the extent of this decomposition
must depend, first, upon the length of time during which they
are exposed to the heated materials, and secondly, upon the
number of particles which are in contact with the red hot
surface, consequently it will be diminished, first, by removing
the gases rapidly from the retort, and secondly, by the mixture
of the illuminating constituents with the non-illuminating
ones ; for it is evident that the number of particles of olefiant
gas in contact with a, given surface, would only be half so great
if this gas were diluted with an equal volume of hydrogen, as
it would be without such an admixture.

Besides the use that has already been mentioned of the
second class or non-illuminating gases, they are of value as
forming a medium for the solution of the vapours of such
hydrocarbons as exist in the liquid or even solid state at the
ordinary temperature of the atmosphere, and they thus ena-
ble us to convert an additional quantity of illuminating
materials into the gaseous form, which they retain perma-
nently unless the temperature fall below the point of satura-
tion. The gain in illuminating power which is thus obtained
will be perhaps better seen from the following example : —
Suppose 100 cubic inches of olefiant gas, allowed to saturate
itself with the vapour of a volatile hydrocarbon, containing
three times as much carbon in a given volume of its vapour as
that contained in an equal volume of olefiant gas, took up or
dissolved three cubic inches of this vapour, then, if we
express the value of 1 cubic inch of olefiant gas by unity, the
illuminating power of the 103 cubic inches of the mixture of
olefiant gas and hydrocarbon vapour will be 109. Now if we
mix these 103 cubic inches with 100 cubic inches of hydrogen,

76

CONTBIBUTIONS TO THE KNOWLEDGE

the mixture will be able to take up an additional three cubic
inches of hydrocarbon vapour, and the illuminating power of
the 206 cubic inches will then become 118; thus the hydro-
gen produces a gain in illuminating power equal to 9 cubic
inches of olefiant gas, or nearly 4*5 per cent, upon the volume
of mixed gases. When we consider that coal naptha con-
tains hydrocarbons of great volatility, and that these are the
surplus remaining after the saturation of the gas from which
they have condensed, the importance of this function of the
non-illuminating class of combustible gases will be sufficiently
evident. I may here remark that incombustible gases could
not be employed for this purpose, since their cooling influence
upon the flame during the subsequent burning of the gas,
would diminish the light to a far greater extent than the
hydrocarbon vapour could increase it.

It is evident that all the three non-illuminating gases form-
ing the second class, would perform both the offices I have
assigned to them perfectly well, and therefore we have as
yet seen no reason for giving our preference in favour of any
one of these diluents ; if, however, we study their behaviour
during combustion, we shall find that where the gas is to be
used for illuminating purposes, hydrogen has qualities which
give it a very decided preference over tlie other two. When
gas is used for lighting the interior of public buildings and
private houses, it is very desirable that it should deteriorate
the air as little as possible, or in other words, it should con-
sume as small a quantity of oxygen, and generate as little
carbonic acid as possible ; and the oppressive heat which is
so frequently felt in apartments lighted with gas will also be
admitted by all to show the advantage of that gas generating
a minimum amount of heat.

The following is a comparison of the properties of the
three non-illuminating gases, in reference to the points just
mentioned : —

1 cubic foot of light carburetted hydrogen, at 60^F. and

OP THE MANUFACTURE Of GAS.

77

SOin. barometrical pressure, consumes 2 cubic feet of oxygen
during its combustion, and generates 1 cubic foot of carbonic
acid, yielding a quantity of heat capable of heating 51bs. 14oz.
of water from 32^ to 212^, or causing a rise of temperature
from 60'^ to SO'S*^ in a room containing 2,500 cubic feet
of. air.

1 cubic foot of carbonic oxide at the same temperature
and pressure, consumes during combustion i a cubic foot of
oxygen, generates one cubic foot of carbonic acid, and affords
heat capable of raising the temperature of lib. 14oz. of
water from 32° to 212'', or that of 2,500 cubic feet of air
from 60° to 66'6°.

1 cubic foot of hydrogen at the same temperature and
pressure consumes i a cubic foot of oxygen, generates no
carbonic acid, and yields heat capable of raising the tempera-
ture of lib. 13oz. of water from 32° to 212°, or that of 2,500
cubic feet of air from 60° to 66'4°.

This comparison shows that light carburetted hydrogen is
very objectionable as a diluent, not only on account of the
carbonic acid which it generates, but also by reason of the
very large quantity of oxygen which it consumes, and the
very great amount of heat which, in relation to its volume,
it evolves on combustion, the consumption of oxygen being
four times and the absolute thermal effect more than three
times as great as that of either of the other gases.

The quantity of heat evolved by the combustion of equal
volumes of carbonic oxide and hydrogen, is nearly, and the
amount of oxygen consumed quite the same, but the carbonic
acid evolved from the first gives a decided preference to
hydrogen as the best diluent.

The same comparison also shows that when the gas is to be
used for heating purposes, and the products of combustion
are carried away, light carburetted hydrogen is by far the
best diluent.

The experiments of Dulong on the absolute thermal effect

78

CONTRIBUTIONS TO THE KNOWLEDGE

of hydrogen, light carburetted hydrogen, and carbonic oxide,
are taken as the basis of the foregoing calculations. Dulong
found that —

1 lb. H raised the temperature of 1 lb. HO through 62471°F.
1 lb. CO " " 1 lb. " 4504°F.

1 lb. CHj « «' 1 lb. " 24244°F.

These considerations indicate the objects that should
chiefly be regarded, in the generating department of the
manufacture of gas for illuminating purposes. They are —

1st. The extraction of the largest possible amount of illu-
minating compounds from a given weight of material.

2nd. The formation of a due proportion of illuminating
and non-illuminating constituents, so that on the one hand
the combustion of the gas shall be perfect, and without the
production of smoke or unpleasant odour, and on the other the
volume of gas required to procure a certain amount of light
shall not be too large.

3rd. The presence of the largest possible proportion of
hydrogen amongst the non-illuminating constituents, to the
exclusion of light carburetted hydrogen and carbonic oxide,
so as to produce the least amount of heat and atmospheric
deterioration in the apartments in which the gas is consumed.

I have not introduced these preliminary remarks to show
the inductive reasoning by which the process of gas-making
described below was arrived at, for I believe that, so far as
the above considerations are concerned, that process was
accidentally adopted ; but I bring them forward to illustrate
and explain the results of the following experiments, and
also to show that a close study of the chemistry of gas-
manufacture would have led to the discovery of this more
philosophical method of gas-generation long ago.

Mr. White's process consists essentially in the generation
of non-illuminating combustible gases by the action of steam
upon charcoal, coke, or other deoxidizing substances, in a

OP THE MANUFACTURE OF GAS.

79

separate retort, and the introduction of these gases, along
with an excess of watery vapour, into the retort in which the
illuminating gases are being generated, and in such a manner
that these latter gases shall be swept out of the retort as
rapidly as possible, and thus removed from the destructive
influence of a high temperature.

The excess of steam accompanying the water gas into the
second retort performs there a remarkable office; it reacts
upon the tar and other fuliginous matter in a manner that
will be described below, and gives rise to the formation of a
large additional quantity of gas, a very large proportion of
which is pure hydrogen. That this reaction of steam should
be confined entirely to the tar and other refuse matters, and
should not affect the luminiferous gases generated in the
same retort, is scarcely conceivable, since the constitution of
tar and of gaseous hydrocarbons is so nearly alike ; but any
destruction of illuminating principles that may be thus caused,
is immensely overbalanced by the quantity of these principles
which are saved from decomposition, by their rapid removal
from the influence of a high temperature and by the vapours
of volatile hydrocarbons with which the water gases remain
more or less saturated.

My first experiments were made upon the application of
the process to resin ; but as these are of less scientific interest
than those on its application to coals and cannels, on account
of there having been no comparative experiments on resin
gas produced by the old process, I will confine myself prin-
cipally to a summary of the results, entering into detail only
on such points as bear upon, and illustrate the principles
which I have laid down.

white's process applied to resin.

These experiments were conducted at the gas works
attached to the mill of Messrs. George Clarke and Co.,
Ancoats, Manchester. These works consisted, at that time,

80

CONTRIBUTIONS TO THE KNOWLEDGE

of a bench containing two resin-gas retorts and two water-
gas retorts of the largest size. The water retorts discharged
themselves into the resin retorts, and these last worked into
a hydraulic main, from which the gas passed successively
through a refrigerator and wet lime purifier to the gas holder,
a vessel of the ordinary construction, and capable of contain-
ing about 18,000 cubic feet.

The volume of gas produced was measured by a meter placed
between the last purifier and the holder; a copper for melting
the resin, and an oil cistern for collecting the residual oil
condensed in the hydraulic main and refrigerator during the
process, completed the apparatus.

Before commencing each experiment, the quantity of gas
in the holder was carefully determined, and a specimen with-
drawn for analysis ; the charcoal retorts were then filled, the
resin melted in the oil of a former working — about 7^ gallons
being used for each 1 l^lbs. of resin, — and the water and oil
tanks being first accurately gauged, the process of gas-making
was commenced by admitting properly regulated streams of
resin and water into their respective retorts.

The temperature of the gas, as it passed through the
meter, was found never to exceed 60°F., and was frequently
much below this point, thus affording a sufficient guarantee
for the correctness of the numbers read ofi".

The specimens of gas were drawn from the holder on the
morning following each experiment, in order to insure perfect
mixture and a fair sample ; and the analyses of these gasea,
as well as those examined in the experiments upon coals and
cannels, were made over mercury, according to methods which
I have fully detailed in the Journal of the Chemical Society,
(vol. ii. p. 269, June, 1849,) with this difference, that a new
form of apparatus was employed, which will be elsewhere
described. This instrument much shortens the processes,
without rendering them less accurate. The volume of the
gases was always read oflF when they were saturated with

OF THE MANUFACTURE OP GAS.

81

watery vapour; the proper correction was afterwards made
for this, and the per centage numbers given in the following
analysis invariably refer to the gases free from watery vapour.
The carbonic acid was determined by caustic potash, the
oxygen by Liebig's new method, viz., by absorption with a
solution of pyrogallic acid in caustic potash, the illuminating
hydrocarbons by strongly fuming sulphuric acid, and the rest
of the gases by explosion with excess of oxygen, in which
the amount of oxygen consumed and carbonic acid generated
were estimated, and the respective volumes of light carburetted
hydrogen, carbonic oxide, hydrogen and nitrogen, calculated
from the numbers thus obtained.

Various attempts have been made to estimate the illu-
minating power of coal and other gases from the analytical
results yielded by them, but hitherto no certain method of
accomplishing this has been established. Dr. Henry regarded
the consumption of oxygen by a given volume of the gas to
be a rough estimate of its illuminating power; but it is
evident that although generally those gases which have the
highest illuminating power consume the largest amount of
oxygen in relation to their volume, yet this is not always the
case, for a gas containing 10 per cent, of olefiant gas, 20
per cent, of light carburetted hydrogen, and 70 per cent, of
hydrogen, would consume much less oxygen during com-
bustion than one containing only 5 per cent, of olefiant gas,
and in which the proportions of light carburetted hydrogen
and hydrogen were reversed, although the illuminating power
of the former would be twice as great.

It will be seen, from what has already been said respecting
the illuminating power of hydrocarbons, that the more dense
these bodies are the greater is the amount of light they yield.
This important fact was first pointed out by Mr. Leigh, who
was also the first to make a near approach towards accurately
estimating the illuminating power of gas from its analysis.
Mr. Leigh regards the illuminating power of coal gas as being

82

CONTRTBUTIOXS TO THE KNOWLEDGE

due to hydrocarbons and light carburetted hydrogen, and the
value of the former as being directly proportionate to the
quantity of oxygen required for their combustion. If we
leave the light carburetted hydrogen entirely out of the
calculation, as I shall prove that this gas has practically no
illuminating power, this method generally gives results not
far from the truth ; but they are, nevertheless, liable to
very considerable error from the fact that the amount of
oxj-gen consumed does not depend alone upon the lumini-
ferous ingredient — the carbon, but also upon the amount of
hydrogen combined with that element, and which is neces-
sarily a variable quantity, being in some of the hydrocarbons
in the ratio C:H=n:n, in others C:H=n:n — 6, and in
some C : H=n : n — 12. In order to avoid this source of
error, and obtain a correct expression for the illuminating
power, however much the composition of the hydrocarbon
may vary, I have estimated the volume of carbon vapour
contained in the luminiferous hydrocarbons, and made that
the basis of the calculation. I have already pointed out a
method for this estimation of the carbon vapour ;* and Mr.
Leigh, in a memoir lately read before this society,f also
describes a similar plan, which he employs for the determi-
nation of the consumption of oxygen by these bodies. The
following is the mode of procedure which I have employed in
the annexed determinations of the value of various hydro-
carbons.

A known quantity of the gas, previous to the action of
fuming sulphuric acid, is exploded with an excess of oxygen,
and the volume of carbonic acid produced accurately noted.
Another known volume of the same gas, after the withdrawal
of the hydrocarbons by sulphuric acid, is then similarly
exploded with oxygen, and the carbonic acid formed also
estimated. Thus, there are determined — 1st, The per centage

* Journal of the Chem. Soc, vol. ii. p. 272. 1849.
t Mem. of the Lit. and Phil. Soc. of Manchester, vol. ix., p. 303. 1851.

OF THK MANUFACTURE OF GAS.

83

amount of hydrocarbons; 2nd, The volume of carbonic acid
generated by hydrocarbons, plus the volume of the same gas
produced by the non-luminiferous gases; and 3rd, The
volume of carbonic acid generated by the non-luminous
gases alone. From these data it is easy to calculate the
amount of carbonic acid generated by one volume of the
hydrocarbons. Thus, if we represent the per centage of
hydrocarbons absorbed by sulphuric acid by A., the volume
of carbonic acid generated by 100 vols, of the original gas by
B., the carbonic acid formed by the gas remaining after the
absorption of hydrocarbons from 100 vols, of original gas by
C, and the volume of carbonic acid generated by the com-
bustion of the hydrocarbons alone by x, we have the follow-
ing equation —

x—c — b ;

and therefore the amount of carbonic acid generated by 1

c b

vol. of the hydrocarbons is represented by — ^ — , but as 1 vol.

A.

of carbon vapour generates 1 vol. of carbonic acid, this

fraction also expresses the quantity of carbon vapour in 1

vol. of the luminiferous constituents. For the purpose of

comparison, however, I prefer to represent the value of

these hydrocarbons in their equivalent volume of olefiant gas,

1 vol. of which contains 2 vols, of carbon vapour ; to effect

this the last expression need only be changed to ^r— ^ Thus

if there exist in a specimen of gas 10 per cent, of hydro-
carbons, one volume of which contains 3 vols, of carbon
vapour, the quantity of olefiant gas to which this 10 per cent,
is equivalent will be 15.

The necessity for this valuation will be evident when I
state that one volume of the hydrocarbons absorbable by
chlorine, or fuming sulphuric acid, (for both these materials
condense precisely the same ingredients if light be perfectly
excluded during the action of the chlorine,) contains quanti-

84

CONTKIBUTIONS TO THE KNOWLEDGE

ties of carbon vapour, varying from 2*54 volumes to 4*36
volumes, from which it is evident that two gases undergoing
the same amount of condensation from the chlorine and sul-
phuric acid tests, might still differ in illuminating power to
the extent of more than 71 per cent.

In his very carefully performed experiments upon Boghead
and Lesmahago cannels. Dr. Fyfe found that practically their
illuminating power was nearly equal, although the quantity
of hydrocarbons contained in the Boghead gas, as shewn by
the chlorine test, was 27 per cent., whilst the Lesmahago gas
contained only 17*6 per cent. ; and Dr. Fyfe suggested that
this equality of light might be owing to our not being yet
acquainted with the method of burning rich gases to ad-
vantage ; but on determining the quantity of carbon con-
tained in equal volumes of the Boghead and Lesmahago
hydrocarbons, I find that 17*6 volumes of the Lesmahago
hydrocarbon contain nearly as much carbon as 27 volumes of
the Boghead hydrocarbon, which satisfactorily demonstrates
this to be the cause of the equality in illuminating power.

The following are the results of the experiments upon the
process applied to resin : —

I— PRACTICAL RESULTS.

Materials Comumed.

Products Obtained.

Average
evolu-
tion of
Gas per

Resin.

Coal.

Charcoal

Lime.

Watr.

Resin
Oil.

Gas.

Gas per
Cwt. of
Resin.

hour.

Cub. feet

Cwt. qr. lb

Cwt. qr.

lb

lb

lb

Galls.

Cb.ft.

Ist Experiment

930

2 1 17i

I 2

10

20

73

10.7

3340

1388

2nd

1000

2 1 18

1 2

12

20

77

7.8

3800

1576

3rd

2 0 17

1 2

12

28

85

4.5

4157

1932

4tli

2 0 7

1 2

10

28

624

8.75

3090

1520

Average production of Gas per ton of Resin 32,080 cubic feet.

Average production of Resin Oil per ton of Resin 70.3 gallons.

Illuminating power of average Gas before purification, as ascertained by shadow
test, .75 cubic feet per hour = light of one short six candle.

OF THE MANUIACTURE OF GAS.

86

ANALYTICAL RESULTS.
COMPOSITION OP GAS BEFORE PURIFICATION.

Actual Ammmt in CvMc Feet. Per Centage Amount.

1st
Exp.

2nd
Exp.

3rd
Exp.

4th
Exp.

>

1st
Exp.

2nd
Exp,

3rd
E.\p.

4th
Exp.

Average.

Hydrocarbona

Light carbd. hydrgn.
Hydrogen

258.7
587.5
1815,3
967.9
210.6

269.0 805.7

1527.7 890.9

1274.8 1976 2
319.2. 753,3
409.6 194.9

7.75
1758
89.38
28-98

6.31

7.08
40.20
83.54

840
10.78

7.41
21.71
47.90
18.26

4.72

8.22
31.09
42.06
15.04

3.59

7.62
27.64
40.72
17.67

6.35

Carbonic oxide

Carbonic acid

3340.0

3800.2 4126.0

100.00

100.00

100.00

100.00

100.00

Amount of Carbon Vapour contained in 1 volume of Hydroca»bons=2.8 volumes.
COMPOSITION OF GAS AFTER PURIFICATION.

1st Exp.

2nd Exp.

3rd Exp.

4th Exp.

Average.

Hydrocarbons

8.27
18.76
42.03
30.93

7.94
45.06
37..59

9.41

7.78
22.79
50.27
19.16

8.53
32.25
43.62
15.60

8 13

Light carburetted hydrogen. .
Hydrogen

29.71
43 38

Carbonic oxide

18 78

100.00

100.00

100.00

100.00

100.00

Specific gravity of average Gas before purificationrr. 65886.
" " after " =.59133.

VALUE OP HYDROCARBONS EXPRESSED IN THEIR EQUIVALENT
VOLUME OF OLEFIANT GAS.

Value of Actual
Amount.

Value of Percent-
age Amount in
Purified Gas.

l.st Experiment
2nd Experiment
3rd Experiment
4th Experiment

362-2 Cubic feet.
376-6 " "
4280 " "

11-58 Cubic feet.
1112 " "
10-89 " "
11-94 " «

The foregoing analytical results furnish us with a satis-
factory explanation of the processes which go on both in the
water and resin gas retorts. In the water retorts two distinct
decompositions take place, viz., first, the decomposition of
steam by charcoal, with the production of equal volumes of

86

CONTKIBtJTIONS TO THE KNOWLEDGE

hydrogen and carbonic oxide gases ; and second, the decom-
position of steam by charcoal, with the formation of two
volumes of hydrogen and one volume of carbonic acid.

The mixture of hydrogen, carbonic oxide, and carbonic
acid along with a large excess of steam, then passes into the
resin retort, where, mixing with the decomposing resin
vapour, it twice traverses the whole length of the red hot
vessel. There is no doubt that the greater portion of water
gas is produced by the decomposition of this excess of steam
in the resin retort, since the weight of charcoal required for
the formation of the volume of water gas generated in each
of the above experiments, is more than twice as great as that
which disappeared from the water retort. This circumstance
elucidates the advantages arising from the passage of this gas,
mixed with steam, through the resin retort; the fuligenous
matter, which would otherwise accumulate and block up this
retort and its pipe, as is well known to be the case when
resin alone is used, is converted into permanent combustible
gas; this, although possessing no illuminating power, yields
valuable service in rapidly sweeping out of the red-hot
retort the permanent illuminating gases produced by the
decomposition of the resin, and in saturating itself with the
various volatile hydrocarbons, upon which so much of the
illuminating power of all gas depends, and which would
otherwise, to a great extent, be left behind with the tar and
water in the condensers. It is well known how rapidly
olefiant gas and all rich hydrocarbons are decomposed into
charcoal and gases, possessing little or no illuminating power
when in contact with the walls of a red-hot retort, and
therefore the value of the water gas in thus rapidly removing
them from this destructive influence, and retaining them in
a permanently gaseous form, can scarcely be over-rated ;
indeed, this principle has not been entirely neglected in the
manufacture of coal gas by the old process, several companies
having attached exhausters to their retorts, which, however,

OF THE MANUFACTURE OF GAS.

87

perform their work very imperfectly, compared with the
water gas.

The generation of water gas free from carbonic acid,
although of no consequence in the process applied to coals
and cannels, is a problem of great importance in its applica-
tion to resin. The relative quantity of this gas produced
varies so considerably, (from 10*78 to 4*72 per cent.,) owing
no doubt to the degree of heat at which the decomposition
takes place, and also probably to the rapidity with which
the water is admitted into the retorts, that it is not impossible,
by varying the condition, to get rid of it altogether. Its
quantity appears to decrease as the temperature increases,
but I have hitherto been unable entirely to prevent its for-
mation. It is therefore requisite to have an efficient means
for removing it from the gaseous mixture before it arrives at
the holder, since this gas is not only entirely useless, being
perfectly incombustible, but has a decidedly injurious influence
on the combustion of the gas, by cooling the flame, and thus
greatly diminishing the illuminating power. Lime, both in
its wet and dry state, is quite inefficient for the removal of
this carbonic acid, since the carbonate of lime first formed
prevents further contact between the gas and the purifying
agent. I therefore recommend caustic soda, produced by
mixing lime with a solution of common soda, as a most
efficient and inexpensive purifying agent when applied in the
following manner : — Let 1 cwt. of soda be dissolved in not
less than 120 gallons of water, (and proportionately for smaller
quantities ;) add to this 70 or 80 lbs. of quick lime ; mix the
whole well together and transfer it to the purifier, where it
should be occasionally well agitated ; after about 8000 cubic
feet of gas have passed through, the mixture should be run oif
and allowed to settle in a suitable tank, from which the clear
liquor floating above the sediment of carbonate of lim.e must
be pumped up into the supply tank for the purifier, and.

88

CONTRIBUTIONS TO THE KNOWLEDGE

being again mixed with the same quantity of lime, used as
before. Thus little or no loss of soda occurs, this base being
simply used as a carrier of the carbonic acid from the gas to
the lime. The sediment of carbonate of lime may be thrown
away between each operation. The cost of purification by
this method would not exceed ^d. per 1000 cubic feet.

The 4th experiment was made with the purifier charged in
the manner described, except that only 75 lbs. of soda were
employed. The result of this experiment shows^ that whilst
the whole of the carbonic acid can be readily removed by this
method, if the caustic soda be employed in sufficient quan-
tity, and the gas brought in contact with a large surface of it,
the quality of the gas is not in the least deteriorated in its
passage through the liquid, as is proved by the increased per
centage of olefiant gas.

A distinction must be made between unpurified coal gas
and unpurified resin gas. The former contains many delete-
rious ingredients, which entirely prevent its use; the latter
does not contain any noxious principle, but simply has its
illuminating power diminished by the presence of carbonic
acid. Its purity of composition and freedom from all sub-
stances which can, during combustion, produce compounds
injurious to furniture, drapery goods, &c., gives the resin gas
great advantages over coal gas, which always contains more
or less bisulphuret of carbon, — which has hitherto defied all
attempts to remove it or diminish its quantity by any process
of purification — and which, during combustion, generates
sulphurous acid, the compound to which all the mischief
produced by coal is probably owing. The odour of the hydro-
carbon gas, while it is sufficiently strong to give warning of
any escape, is far less nauseous than that of the coal gas, and
might even by some persons be deemed pleasant ; whilst the
process of manufacture is so simple, that any person of mode-
rate intellect can at once conduct it.

OF THE MANUFACTURE OF GAS,

89

WHITES PROCESS APPLIED TO COALS AND CANNELS.

The following experiments were conducted at the same
works, and with the same apparatus as those on the process
applied to resin ; but in order to obtain a fair comparison of
the results yielded by the various coals when distilled alone,
as in the usual process of gas making, with those obtained
from the same coals when treated with water gas, according
to the new process, each coal was distilled first by itself, and
then with the addition of water-gas, equal weights being
used for each experiment ; but as smaller quantities of gas
were produced in these experiments than in the previous
ones on resin, it was necessary to avoid any error which
might arise from intermixture of the gases filling the small
refrigerator, purifiers, &c., between the retorts and the
holder, previous to the commencement of each experiment,
and therefore the capacity of these vessels was determined,
and a quantity of gas considerably greater than requisite to
fill them, and made under the same circumstances as that in
the succeeding experiment, was passed through them before
each trial commenced. This plan of clearing out the vessels
and pipes was found to answer perfectly on testing it by
passing alternately similar quantities of Wigan cannel gas
and water-gas through them, and the observation of the num-
ber of feet indicated by the meter before the flame of a test
burner, coming from the ingress pipe near the holder, fully
assumed the illuminating power of the gas which was being
produced.

This precaution being adopted, each experiment was com-
menced by charging one of the retorts, thoroughly cleaned
out, with 1 cwt. of coal or cannel, which was distributed
nearly equally between the upper and lower divisions ; the
lid being then replaced as quickly as possible, the distillation
was continued, either with or without the addition of water
gas, until all volatile matters were expelled from the coal

N

90

COKTBIBUTIONS TO THE KNOWLEDGE

retort. The water gas was produced, as usual, by allowing
a thin stream of water to fall upon charcoal heated to full
redness in a separate retort ; this gas, along with the excess
of steam, then passed into the lower division of the coal
retort, sweeping in its course the gases forming in both the
lower and upper divisions rapidly into the hydraulic main,
and producing, in its passage, an additional quantity of
water gas by the action of the steam upon the coal tar. The
production of the water gas was so regulated as to be most
rapid at the commencement of the experiment, and then
gradually to decline to its close.

For the purification of the gases nothing more was used
than two small purifiers, the one containing wet and the
other di'Y lime ; but on the large scale, arrangements ought
to be made for removing ammonia as well as sulphuretted
hydrogen. There is, however, no constituent contained in
the gases made by the new process applied to coals, which
requires means of purification different from those commonly
used in all gas works.

The samples of gases employed for testing the illuminating
power and for analysis, were collected in the following man-
ner : — The main conveying the gas from the purifiers to the
holder was tapped at a point just before it entered the meter,
and a tube attached leading to a graduated gas-holder capable
of containing 80 cubic feet. The flow of gas into this holder was
so regulated by a stop-cock as to allow the admission of a cer-
tain per centage throughout the entire working; for instance,
if a 10 per cent, sample was being taken, 10 feet entered this
holder during the time 90 feet passed through the meter.
The per centages varied from 3 to 10 in the diiferent experi-
ments, but they were always made as large as the size of the
holder rendered practicable. The volume of gas thus extracted
was noted, and added to the quantity indicated by the meter.
This method is much more convenient and accurate than
when a large holder is employed and the total quantity of

OF THE MANGFACTUKE OF GAS.

91

gas operated upon, since a large holder, even when depressed
to the greatest extent, must always contain a considerable
quantity of gas from the previous operation, and thus the
experiment is vitiated ; whilst with a smaller vessel, this
residue can always be got rid of by allowing a few cubic feet
of the gas at the time generating, to blow through it simul-
taneously with the collection of the first portion of the
sample.

A rather low heat was employed in all the experiments, as
it was found to be the best as well for the coals alone as with
water gas ; and the results obtained in the trials of the coals
without water gas, will rarely be found below those of other
experimenters.

The temperature of the gases on reaching the meter was
found to be no higher than that of the external atmosphere.
The greatest care was taken to secure accuracy in the results
and perfect fairness in the comparison between the coals
distilled alone and with water gas. All the weighings were
made before me, and every experiment from beginning to
end was made under my own personal inspection.

The illuminating power was tested by Bunsen's Photo-
meter,— a large number of the experiments being made with
an improved form of the instrument, invented by Messrs.
Church and Mann, of the City Gas Works, London. In
some instances, the shadow test was also tried. The size of
burner and pressure of gas were in most cases noted, and in
every instance the determination of the illuminating power
was made when the gas was burning to the greatest advantage,
that is, without a flickering flame or a tendency to smoke.
These experiments are, however, even with the greatest
care, subject to certain errors, caused principally by the irre-
gular burning of the spermaceti candle, rendering them only
approximative. The liability to these errors has, it is true,
been much reduced by the ingenious plan of substituting a

92

CONTKIBDTIONS TO THE KNOWLEDGE

jet of gas for the candle, as proposed by Mr. King and Mr.
Wright ; but yet the impossibility of accurately ascertaining
the consumption of the candle, at the moment when the gas-
jet is made equal to it, renders the experiments still liable to
small inaccuracies. The following results are all corrected
to those which would have been obtained by using a sperm
candle burning 120 grs. per hour; and one of these candles
burning 10 hours, is taken as the standard with which to com-
pare the total quantity of light yielded by a given volume of
gas. Thus, when it is stated that the total quantity of gas
produced from 1 cwt. of coal, when burnt at the rate of 5 feet
per hour, is equal to 546 candles, it is intended that the
light afforded by the gas is equal to that yielded by 546
sperm candles, each burning 10 hours, and at the rate of
120 grs. per hour.

The following are the results of the experiments : —

WIGAN CANNEL, (INCE HALL.)

I.— WITHOUT WATER GAS.

Cannel used 1 cwt.

Gas prodaced 545 cubic feet.

Coke left 74 lbs.

Time occupied 3h. 20m.

ILLUMINATING POWER OF GAS.

Shadow Test.

3 cubic feet
per hour.

3 cubic feet
per hour.

4 cubic feet
per hour.

5 cubic feet
per hour.

^ cubic feet per hour
= 1 candle.

Fish-tail No. 1.

Press. .3 in.

»= 8.77 candles.

Fish-tail No. 1.

Press. .4 in.
»= 13.9 candles.

Fish-tail No. 3.

Press. .6 in.
== 18.0 candles.

Fish-tail No. 4.

Press. .5 in.
= 33.1 candles.

Total gas produced when burnt at 5 feet per hour, yields
light = 240*8 sperm candles.

OF THE MANOFAOTOEE OF GA8.

PER CENTAGE COMPOSITION OP DRY GAS.

Hydrocarbons and defiant gas, equivalent to lfl*13

per cent, of defiant gas 1081

Light carburetted hydrogen 41'99

Hydrogen 35 94

Carbonic oxide 10*07

Carbonic acid 119

Nitrogen ) .

[ traces

Oxygen J

10000

98

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 58'05=81-27 olefiant gasi

Light carburetted hydrogen 225"48

Hydrogen 19300

Carbonic oxide S4'07

Carbonic acid C'39

Watery vapour* 801

S4500

Amount of carbonic gas generated by 1 volume of hydro-
carbons, &c., condensed by fuming sulphuric acid, = 2*8
volumes.

n.-WlTH WATER GAS.

Cannel used 112 lbs.

Gas produced 806 cubic feet.

Coke left 68 lbs.

Timeoccupied 3h. 20 m.

* It was found quite impossible to determine the quantity of watery vapour
contained in each gas as it passed through the meter, since both the tempera-
ture of the gas and the degree of saturation were subject to variations during
each experiment ; a mean amount of 147 per cent, has therefore been assumed
as the watery vapour present in each case. Although this number is not
absolutely accurate, it is more than sufficiently so for all practical purposes.

94

CONTRTBDTIONS TO THE KNOWLEDGE

ILLUMINATING POWER OP GAS.

Shadow Test.

.576 cubic feet per

hour

= 1 candle.

2 feet per hour. 3 feet per hour.

Fish-tail No. 2.

Press. .7 in.

= 8.6 candles.

Fish-tail No. 2.

Press. .6 in.
= 13.7 candles.

4 feet per hour.

Fish-tail No. 2.

Press. .6 in.

= 15,8 candles.

5 feet per hour.

Fish-tail No. 4.

Press. .5 in.

= 20 candles.

Total gas produced when burnt at the rate of 5 feet per
hour, yields light = 322*4 sperm, candles.

PER CENTAGE COMPOSITION OF DRY GAS.

Hydrocarbons and defiant gas equivalent to 13 72 per |

cent, defiant gaa J

Light carburetted hydrogen 27*20

Hydrogen 47'39

Carbonic oxide ]4'86

Carbonic acid 0*00

Oxygen and Nitrogen, (traces)

10000

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and defiant gas 83-77=1 08*9 defiant gajs.

Light carburetted hydrogen 215*97

Hydrogen 376*28

Carbonic oxide 117*99

Watery vapour 11*99

806*00

Amount of carbonic acid generated by 1 volume of con-
densible hydrocarbons = 2*60 volumes.

>■

Per cwt.
6 candles.

Hence gain in illuminating power by
the employment of water gas .

And gain in defiant gas =27*63 cub. ft,

Gain in quantity of gas =261 " "

Per ton,
1632 candles.

352*6 cub. ft.
5*220 " "

Per cent.
33*9 candles.

34 cub. ft.
47*9 " "

OF THE MANDFACTURE OF GAS.

95

BOGHEAD CANNEL.

I.— WITHOUT WATER GAS.

Cannel used 112 lbs.

Gas produced 662 cubic feet.

Coke left 36 lbs.

Time occupied 2h,55m.

ILLUMINATING POWER OF GAS.

Shadow Test.

1 foot per hour.

2 feet per hour.

3 feet per hour.

5 feet per hour.

.325 cubic feet pei

hour

= 1 candle.

Fish-tail burner.*

Press, .9 in,
--= 6.48 candles.

Ksh-taiL

Press. 1.2 in.

= 14.4 candles.

Fish-tail.

Press. .6 in.

= 25.7 candles.

Winfield's
Button Burner.
= 52.6 candles.

Total gas produced when burnt at the rate of 3 feet per
hour, yields light = 567 sperm candles.

PER CENTAGE COMPOSITION OF DRY GAS.

Hydrocarbons and defiant gas equivalent to 3 1' 11

per cent, olefiant gas 24*50

Light carburetted hydrogen 5838

Hydrogen 10'54

Carbonic oxide 658

Carbonic acid 0*00

JOOOO

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 1 59*7 =202*8 olefiant gas.

Light carburetted hydrogen 380'8

Hydrogen 68*8

Carbonic oxide 429

Aqueous vapour 9.8

6620

* The fish-tail burners used in these experiments were very small, and made
expressly for this exceedingly rich gas.

06

CONTRIBUTIONS TO THE KNOWLEDGE

Amount of carbonic acid generated by 1 volume of hydro-
carbons, condensed by fuming sulphuric acid=2'54 volumes.

II.— WITH WATER GAS.

Cannel ased 112 lbs.

Gas produced 1908 cnbic feet.

Coke kit 37i lbs.

Time occupied Shears.

ILLUMINATING POWER OP GAS.

Shadow
Test.

2 feet
per hour.

3 feet
per hour.

4 feet
per hour.

5 feet
per hour.

8 feet
per hour.

425 cubic feet
per hour
= 1 candle.

Fish-tail No. 1.

Press. .3 in.
= 11.2 candles.

Fish-taU No. 2.

Press.
= 16.8 candles.

Fish-tail No. 4,

Press. .4 in.
= 20,0 candles.

Fish-tail No. 4.

Press. .6 in.
= 29.7 candles.

Winfield's

Burner.

= 50.6 candles.

Total gas produced when burnt at the rate of 3 feet per
hour, yields light = 1068'4^.

PER CENTAGE COMPOSITION OF DRY GAS.

Hydrocarbons and olefiant gas equivalent to 1984

per cent, olefiant gas I4'12

Light carburetted hydrogen 22'25

Hydrogen 4551

Carbonic oxide 14 34

Carbonic acid 3'78

10000

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 265"5=373 olefiant gas.

Light carburetted hydrogen 418"2

Hydrogen 855'5

Carbonic oxide 269'6

Carbonic acid 710

Aqueous vapour 28 2

19080

OF THE MANDFACTURE OF GAS.

»7

Amount of carbonic acid generated by 1 volume of con-
densible hydrocarbons =281 volumes.

Per owt,
Hence gain in iilominating power "^

by the employment of water gas

And gain in oleiiant gas 170.2 cub. ft,

Gain in quantity of gas 1246 " **

f 501.4 candles.
J

Per ton,
10.028 candles

3404 cub. ft.
24920 " "

Per cent.

88.4 candles.

83.9 cub. ft.
188.2 " "

NOTB.— The following Is the per centage composition of this extraordinary
cannel according to the mean of two analyses made with great care by my
assistant Mr. Russell : —

Carbon 6S.34

Hydrogen 9.12

Oxygen 5.46

Nitrogen 71

Sulphur 16

Water 64

Ash 18.68

100.00

In this experiment it was found impossible to generate
more than one half of the requisite quantity of water gas
from the water retort connected with that in which the
cannel was distilled, and consequently another water retort
had to be employed ; but this, instead of pouring its gas into
the coal retort, delivered it directly into the hydraulic main ;
thus reducing the advantageous operation of the water gas in
rapidly sweeping out the illuminating gases from the coal
retort, and, in addition, preventing the removal of a consider-
able amount of carbonic acid, which materially diminished
the illuminating power, as indicated by the photometer.

I have since had the opportunity of repeating the experi-
ment with a new apparatus, consisting of one coal and two
water retorts, both of the latter delivering their gas into the
lower division of the former: the other conditions of the
experiment were the same as before.

98

CONTRIBUTIONS TO THE KNOWLEDGE

SECOND EXPERIMENT.

Cannel Dsed 112 lbs.

Gas produced 2586 cubic feet.

Time occupied ^ 3h. 15m.

ILLUMINATING POWER OP GAS.

2 feet per hour.

3 feet per hour.

4 feet per hour.

5 feet per hour.

5 feet per hour.

Ksh-tafl No. 1.
6 candles.

Fish-tail No. 1.
10.1 candles.

Rsh-tail No. 4.
15.1 candles.

Fish-tail No. 4.
17.9 candles.

Leslie's Burner
20.0 candles.

Total gas produced when burnt at the rate of 5 feet per
hour, yields light = 1034.4 sperm candles.

Hence gain in illuminating power
by application of water gas
process

Gain in quantity of gas

Per cwt.
467.4 candles.
1924 cub. ft.

Per ton.

934.8 candles.

38,480 cub. ft.

Per cent.
82.4
290.6 cub. ft.

No analyses were made in connection with this experi-
ment, but it was carefully ascertained that the gas did not
contain more than a mere trace of carbonic acid.

The experiment thus demonstrates the fact that the whole
of the carbonic acid is removed from the water gas during its
passage through the coal retort, even when Boghead cannel is
employed, and also that the enormous quantity of 51,720
cubic feet of gas, possessing a high illuminating power, is
capable of being produced from 1 ton of the Boghead cannel ;
but it does not show, as might have been expected, that the
additional quantity of water gas passed through the coal
retort has had the ejffect of preserving more of the illumi-
nating hydrocarbons than in the previous experiment ; on the

OF THE MANUFACTURE OF OAS.

99

contrary, a slight diminution of total illuminating power is
seen on comparing the results of the two experiments. But
this diminution is accounted for, when we consider that the
first experiment was made in summer, whilst the last was
performed during the last frost and with the holder covered
with snow; the gas therefore passed through a species of
ice-test, and suffered a small diminution of illuminating
power, the extent of which we shall speak of presently.

LESMAHAGO CANNEL.

I.— WITHOUT WATER GAS.

Cannel used 1121b8.

Gas produced 531 cubic feet.

Coke left 54ilbs.

Time occupied 3h, 20m.

ILLUMINATING POWER OP GAS.

Shadow Test.

2 feet per hoiir.

3 feet per hour.

4 feet per hour.

4i feet per hour.

,85 cubic feet per hour
= 1 candle.

Fish-taQ No. 1,

Press. .6 m.
= 12.1 candles.

Fish-tail No. 1.

Press. .6 in.
- 33.3 candles.

Fish-taU No, 3.

Press, .5 in,
= 38,7 candles.

Fish-taQ No. 3.
Press. .6 in.
= 36 candles.

Total quantity of gas when burnt at the rate of 4 feet per
hour, yields light = 381 sperm candles.

PER CENTAGE COMPOSITION OP i)RY GAS.

Hydrocarbons and defiant gas eqilivalent to 28.30 pet

cent, defiant gas .; 16.31

Light carburetted hydrogen 42.01

Hydrogen 26.84

Carbonic oxide 14.18

Carbonic acid gQ

Oxygen and nitrogen (traces) .

100.00

100

CONTETBUTIONS TO THE KNOWLEDGE

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 8S.3 = 148 olefiant gas.

Light carburetted hydrogen 219.8

Hydrogen 140.6

Carbonic oxide 74.2

Carbonic acid 3.4

Aqueoos vapour 7.8

531.0

Amount of carbonic acid produced by 1 volume of conden-
sible hydrocarbons = 3.47 volumes.

II.— WITH WATER GAS.

Cannel used l]21bs.

Gas produced 1459 cubic feet.

Coke left 49 lbs.

Time occupied 3h. 18m.

ILLUMINATING POWER OP GAS.

Shaaow Test.

2 feet per liour.

3 feet per hour.

4 feet per hour.

5 feet per hour.

.5 cubic feet per hour
= 1 candle.

Fish-tsdl No. 3.
Press. .5 in.
= 9-3 candles.

Fish-tail No. 2.

Press. .6 in.

= 13.2 candles.

Fish-tail No. 2.

Press. ,6 in.
= 191 candles.

Fish-taU No. 4.

Press. .5 in.
= 2S.7 candles.

Total quantity of gas when burnt at the rate of 4 feet per
hour, yields light = 696.7 sperm candles.

PER CENTAGE COMPOSITION OF DRY GAS.

Hydrocarbons and defiant gas equivalent to 19.05

per cent, defiant gas 10.89

Light carburetted hydrogen 18.94

Hydrogen 55.09

Carbonic oxide 15.02

Carbonic acid .06

100.00

OF THE MANUFACTURE OF GAS.

101

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and defiant gas 156.5 = 273.9 olcfiant gas-

LJght carburetted hydrogen 272.3

Hydrogen 791.9

Carbonic oxide 215.9

Carbonic acid 9

Aqueous vapour 21.5

1459.0

Amount of carbonic acid generated by 1 volume of conden-
sible hydrocarbons = 3.50 volumes*

Gain in illuminating power by appli-
cation of water gas =

Gain in quantity of olofiant gas ...

Gain in total quantity of gas pro-
duced

Per cwt.

315.7 candles.
125,9 cub. ft.

928 «

Per ton.

6314 candles.
2518 cub. ft

18,560 "

Per cent.

82.8
85.1

174.8

METHYL CANNEL.

I.— WITHOUT WATER GAS.

Cannel used 112Ib8.

Gas produced 478 cubic feet.

Coke loft 51 lbs.

Time occnpied 3 hours.

ILLUMINATING POWER OP GAS.

1 foot per hoar.

2 feet per hoar.

3 feet per hour.

4 feet per hour.

5 feet per hour.

FUh-tail No. 1
= 8.7 candles.

Fish-taU No. 1.
= 10.1 candles.

Fish-tail No. 1,
= 17.4 candles,

Fish-tail No. 2.
= 21,5 candles.

Fish-tail No, 3.
= 27,8 candles.

Illuminating power of total gas burnt at the rate of 5 feet
per hour = 265.8 candles.

102

CONTBIBUTIONS TO THE KNOWLEDGE

PErf*CENTAGE COMPOSTION OF GAS.
Hydrocarbons and olefiant gas equivalent to 18.53

per cent olefiant gas 14.48

Light carburetted hydrogen 38.76

Hydrogen 33,32

Carbonic oxide 13.40

Carbonic acid .05

Nitrogen and Oxygen, (traces) — ^

100.00

Amount of carbonic acid generated by 1 volume of conden-
sible hydrocarbons = 2.56 volumes.

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 68.2=87.3 olefiant gas.

Light carburetted hydrogen 182.5

Hydrogen 156.9

Carbonic oxidei 63.1

Carbonic acid .3

Aqueous vapour 7.0

478.0

11.— WITH WATER GAS.

Cannel used 1121bs.

Gas produced 1320 cubic feet.

Coke left 61 lbs.

Time 3 hours.

ILLUMINATING POWER OF GAS.

2 feet per hour.

3 feet per hour.

4 feet per hour.

5 feet per hour.

FUh-taU No 1.
= 7i2 candles.

Fish-tail No. 2.
= 10.7 candles.

Fish-tail No. 2.
= 15.3 candles.

Fish-tail No. 4.
= 21 candles.

Illuminating power of total quantity of gas burnt at the
rate of 5 feet per hour = 554.4 candles.

OF THE MANUFACTURE OF OAS.

103

PER CENTAGE COMPOSITON OP GAS.

Hydrocarbons and olefiant gas equivalent to 14.05

per cent, olefiant gas 11.06

Light carburetted hydrogen .-. 22.89

Hydrogen 45.58

Carbonic oxide 20.44

Carbonic acid ,03

Nitrogen and Oxygen, (traces)

100.00

Amount of carbonic acid generated by 1 volume of conden-
sible hjdrocarbons=S.54 volumes.

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 143.8=182.6 olefiant gas.

Light carburetted hydrogen 297.8

Hydrogen 592.7

Carbonic oxide 265.8

Carbonic acid .4

Aqueous vapour 19.5

1320.0

Gain in illuminating power by appli-
cation of water gas =

Gain in quantity of olefiant gas ...
Gain in quantity of gas

Per cwt.

288.6 candles.

95.3 cub. ft.

842 " "

Per ton.

5772 candles.
1906 cub. ft.
16,840 « "

Per cent.

108.6
109.2
176.2

NEWCASTLE CANNEL, (RAMSAY'S.)

I.— WITHOUT WATER GAS.

Cannel used 1121bs,

Gas produced 515 cubic feet.

Coke left 7441bs.

Time occupied 3h. 25m.

104

CONTRIBUTIONS TO THE KNOWLEDGE

ILLUMINATING POWER OF GAS.

Shadow Te8t.

2 feet per hour.

3 feet per hour.

4 feet per hour.

6 feet per hour.

.575 cubic feet per
hour = 1 candle,

Ksh-taa No. 1.

Press. .4 in.
= 8.4 candles.

Hsh-taU No. 1.

Press. .5 in.

= 11.9 candles.

Fish-taU No. 1.

Press. .8 in.
= 30.0 candles.

Rsh-tafl No. 2.

Press. ,8 iu.
= 24.5 candles.

Illuminating power of total gas when burnt at the rate of 5
feet per hour = 252.3 sperm candles.

PER CENTAGE COMPOSITION OF GAS.

Hydrocarbons and olefiant gas equivalent to 16.94

per cent defiant gas 9-68

Light carburetted hydrogen 41.38

Hydrogen 33.30

Carbonic oxide 15.64

Carbonic acid 0.00

100.00

Amount of carbonic acid generated by 1 volume of conden-
sible hydrocarbons = 3.50 volumes.

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 491=85-9 olefiant gas.

Light carburetted hydrogen 2100

Hydrogen 168-9

Carbonic oxide 79*4

Aqueous vapour 7.6

515.0

II.— WITH WATER GAS.

Cannel used 1121bs.

Gas produced 751 cubic feet.

Coke left 74 lbs.

Timeoccupied 3h. 25m.

OF THE MANUFACTURK OF OAS.

106

ILLUMINATING POWER OF GAS.

Shadow Test.

2 feet per hour.

3 feet per hour.

4 feet per hour.

5 feet per hour.

6 feet per hour.

-725 cubic feet

per hour

= 1 candle.

Fish-taU No. 2.

Press. .4 in.
= 5.8 candies.

Fish-fe^U No. 2.

Press, .6 in,
= 10,3 candles.

Fish-tail No. 2.

Press. .6 in,
= 14,1 candles.

JFi8h-taaNo,4.

Press. .8 in,
= 18.8 candles.

Fish-tail No, 4.
Press. .7 in.
23.2 candles.

Illuminating power of total gas when burnt at the rate of
5 feet per hour = 282.3 sperm candles.

PER CENTAGE COMPOSITION OF GAS.

Hydrocarbons and olefiant gas equivalent to 13.15

per cent, defiant gas 9.04

Light carburetted hydrogen 26.84

Hydrogen 44.26

Carbonic oxide 19.39

Carbonic acid .47

100,00

Amount of carbonic acid generated by 1 volume of conden-
sible hydrocarbons = 2.91 volumes.

ACTUAL CONSTITUENTS.

Cubic feet.

Hydrocarbons and olefiant gas 66.9=97.3 olefiant gas.

Light carburetted hydrogen 198.6

Hydrogen 327.5

Carbonic oxide 143.5

Carbonic acid 3.4

Aqueous vapour 11.1

761.0

Hence —

Gain in illumuiating power by the

employment of water gas =

Gain in quantity of defiant gas ...
Gain ia total quantity of gas

Per owt.

30 candles.

11.4 cub. ft.

236 " •*

Per ton.

600 candles.
228 cub. ft.
4720 " «

Per cent.

11.2,
13.3
45.8

106

C0NTBTBDTI0N8 TO THE KNOWLEDGE

The results yielded by this cannel are very different from
those obtained with the same material at the Western Gas
Worlcs, London. Mr. "Wright, the eminent engineer to the
Western Gas Company, has lately made a series of experi-
ments, conducted with great care and accuracy, upon the gas
there produced, and states that a flame consuming 3 feet per
hour produced light equal to from 16.6 to 20 candles ; and
this statement is perfectly corroborated by my own analysis
of a specimen of the Western Company's gas collected June
15th, 1851, and given below. As I have not had an oppor-
tunity of repeating the practical examination, I can only
reconcile these discordant results by supposing either that
the specimen of Newcastle cannel sent me for investi-
gation was of inferior quality, or that some unknown
disturbing cause interfered with my experiments upon it.
I should anticipate that at least 29,000 cubic feet of gas per
ton, with an illuminating power equal to 20 candles for a
consumption of 5 feet per hour, could be obtained from this
cannel by the application of water gas, if of the same
quality as that used at the Western Gas Company's works,
Faddington.

WIGAN CANNEL, (BALCARRES.)

I.— WITHOUT WATER GAS.

Cannel used 112 lbs.

Qas produced 522 cubic feet.

Coke left 68^ lbs.

Time occupied 3h. 25m.

ILLUMINATING POWER OF GAS.

Shadow Test.

2 feet per hour.

3 feet per hour.

4 feet per hour.

6 feet per hour.

.675 cubic feet per
hour =» 1 candle.

Ksh-taU No. 3.

Press. A in.
= 6.0 candles.

Fish-tail No. 3.

Press. .5 in.
<= 10.9 candles.

Fish-tail No. 2.

Press. ,6 in.

= li.7 candles.

Firii-taU No. 4.

Press, .6 in.
= 19.9 candles.

OF THE MANUFACTURE OF GAS. 107

Illuminating power of total gas when burnt at the rate of
5 feet per hour = 207.8 candles.

No analyses of this and the following specimen of gas were
made.

II.— WITH WATER GAS.

Cannel used 112 lbs.

Gasprodaoed 775 cubic feet.

Coke 67|lbs.

Time occupied 3h. IS m.

ILLUMINATING POWER OF GAS.

Shadow Test.

2 feet per hour.

3 feet per hour.

4 feet per hour.

5 feet per hour.

7 cubic feet per hour
= 1 candle.

Fish-taU No. 1.

Press. .4 in.
= 5.6 candles.

Fish-tail No. 3.

Press. A in.

" 9,6 candles.

Fish-tail No. 3.

Press. .6 in.
= 14.1 candles.

Fish-tail No. 4.

Press, .6 in.
= 19.1 candles.

Illuminating power of total gas when burnt at the rate of 5
feet per hour = 296 candles.

Hence —

Gain in illominating power by the

employment of water gas ... =

Gain in total quantity of gas ... =

Per owt.

88.2 candles.
253 cubic feet.

Per ton.

1764 candles.
5060 cubic ft,

Per cent.

42.4
48.5

NEWCASTLE COAL, (PELTON.)

I have not ascertained the results which this coal yields
with water gas, owing to an experiment which I made being
rendered useless by the occurrence of a leakage in the appa*
ratus, the sample of coal at my disposal being so nearly
exhausted as not to leave a sufficient quantity for a repetition
of the trial. The following examination of the gas produced
from the coal distilled without water gas, may not, however,
prove entirely uninteresting.

108

CONTRIBUTIONS TO THE KNOWLEDGE

NEWCASTLE COAL, (PELTON.)

WITHOUT WATEK GAS.

Coal used 112 lbs.

Gas produced 504 cubic feet.

Coke left 70 lbs.

ILLUMINATING POWER OF GAS.

2 feet per hour.

3 feet per hour.

4 feet per hour.

5 feet per hour.

6 feet per hour.

Kgh-tail No. 1,
Press. = .6 in.
= 46 candles.

Fish-tail No. 2.

Press. .6 in.
= 8.8 caadles.

Fish-taU No. 3.

Press. .4 in.
= 12.15 candles.

Fish-tail No. 4.

Press. .4 in.
== 14.9 candles

Fish-tail No. 4.

Press. .6 in.
= 17.0 candles.

Illuminating power of total gas when burnt at the rate of
5 feet per hour = 150.2 candles.

PER CENTAGE COMPOSITION OF GAS.

Hydro-carbons and olefiant gEis equivalent to 7.16

percent, olefiant gas 3.87

Light carburetted hydrogen 32.87

Hydrogen 60.05

Carbonic oxide 12.89

Carbonic acid .32

Nitrogen and oxygen (traces)...

100.00

Amount of carbonic acid generated by 1 volume of conden-
sible hydrocarbons = 3.70 volumes.

ACTUAL CONSTITUENTS.

(Jubic feet.

Hydro-carbons and olefiant gas 1 9.2= 35.5 olefiant gas.

Light earburetted hydrogen 163.2

Hydrogen 248i5

Carbonic oxide 64.0

Carbonic acid 1,6

Aqueous vapour 7.5

504.0

OF THE MANUFACTUBE OF GAS. • 109

The foregoing experiments give us a much more complete
insight into this process of gas making than did the previous
ones on resin gas; and they also bring to light several circum-
stances highly favourable to it, which could scarcely have
been predicted previous to the actual trials being made. The
first and most important of these is the disappearance of the
carbonic acid contained in the water gas during its passage
through the coal retort. This disappearance is so complete
that the resulting gaseous mixture actually contains a much
smaller percentage than does the gas obtained by the distilla-
tion of the coal alone. It is true that the gases examined in
the above experiments had streamed through small wet and
dry lime purifiers ; but I have shown that in the production
of gas from resin, lime \fras almost useless for removing car-
bonic acid in these purifiers, and that, even when charged with
caustic soda, they still left 3.59 per cent, in the gas. It is
therefore certain, that the carbonic acid of the water gas is de-
stroyed by some action taking place during its passage through
the coal retort ; thus obviating all trouble and expense of
removing this gas by any purifying process whatever. There
is little doubt that this removal of the carbonic acid depends
upon its conversion into carbonic oxide gas by the carbon-
aceous matters in the coal retort ; and of these the coke is
probably the most active, since the volatile matters do not
differ materially from those produced during the distillation
of resin; and these, we have seen, fail to remove the acid gas*

Another favourable circumstance occurring in the process
consists in the relatively small quantity of carbonic oxide that
is produced ; a large proportion of this gas would be equally
objectionable with a high per centage of light carburetted
hydrogen, so far as the quantity of carbonic acid formed
during its subsequent combustion is concerned; a reference
to the composition of the foregoing gases shows us, however,
that in all cases the amount of carbonic acid generated is less
than that formed by the combustion of an equal volume of

110

CONTBIBUTIONS TO THE KNOWLEDGE

the gas obtained from the same coals by the ordinary process
of manufacture, and in some cases it is even less than that
produced by a pure coal gas flame giving an equal light.
The following table shows this comparison: —

Name of Gas.

Cubic feet of carbonic acid
produced by combustion
of 100 cubic feet of gas.

Cubic feet of carbonic acid
produced per hour by a
light equal to 20 candles.

Ince Hall cannel

83.5
69.5
89.3
71.5
. 90.9
72.8

113.9
72.1

127.2
76.3

3.76

Ditto with water gas

3.47

Methyl cannel

3.32

Ditto with water gas

3.40

Ramsay's Newcastle cannel

3.64

Ditto with water gas

3.86

Lesmahago cannel

2.95

Ditto with water gas

3.02

Boghead cannel

2.96

Ditto with water gas

3.05

The favourable position which the gases made by the new
process occupy in the above comparison, could not have been
attained if the whole or even a very large portion of the
water gas had been generated in the charcoal retort; for
when water gas alone is so generated, it is found to consist
of hydrogen and carbonic oxide, mixed with quantities of
carbonic acid, varying from 0 to 15 per cent, according to
the heat employed and other circumstances. When the per
centage of the acid gas is 0, then the volumes of hydrogen
and carbonic oxide are equal ; and as no important quantity
of carbonic acid was ultimately present in the gases produced
in the foregoing experiments, the whole of that gas entering
the coal retort must be converted into carbonic oxide, and
therefore we may consider the water gas entering the coal
retort as being composed of equal volumes of hydrogen and
carbonic oxide. Now, if the increase in the total quantity of
gas produced by the application of the new process to any
given coal or cannel, were due only to the water gas formed
ill the charcoal retort, it is obvious that the gain in carbonic

OF THE MANUFACTURE OF GAS.

Ill

oxide ought to be equal to the gain in hydrogen ; but a
glance at the analytical results shows that this is far from
being the case; thus with —

BOGHEAD CANNEL.

The gain in hydrogen = 786.9 cubic feet.

And " carbonic oxide = 226.7 "

Hence, gain in hydrogen : gain in carbonic oxide = 3.5 : 1.

With—

LESMAHAGO CANNEL.

The gain in hydrogen = 661.2 cubic feet.

And " carbonic oxide = 141.6 "

Hence, gain in hydrogen : gain in carbonic oxide = 4.6 : 1.
With—

INCE HALL CANNEL.

The gain in hydrogen ...... = 183 cubio feet.

And " carbonic oxide = 63.9 "

Hence, gain in hydrogen : gain in carbonic oxide = 2.9 : 1 .
With—

RAMSAY'S NEWCASTLE CANNEL.

The gain in hydrogen = 158.7 cubic feet.

And " carbonic oxide = 64.2 "

Hence, gain in hydrogen : gain in carbonic oxide = 2.5 : 1 .
And with —

METHYL CANNEL.

The gain in hydrogen = 435.6 cubic feet.

And " carbonic oxide — 202.6 "

Hence, gain in hydrogen : is to gain in carbonic oxide =
2.2: 1.

It is therefore evident, that a large quantity of water gas
must be generated by the action of steam upon the carbon-
aceous materials in the coal retort, and that this water gas

112

CONRTIBDTTONS TO THE KNOWLEDGE

contains a very much greater per centage of hydrogen than
that produced in the charcoal retort. Although we are not
yet sufiiciently acquainted with the action of watery vapour
upon organic substances at high temperature, to state posi-
tively the cause of this excess of hydrogen, yet there can be
little doubt that it is derived from the action of steam upon
the hydrocarbons of the tar ; for as watery vapour in acting
upon carbon transfers its oxygen to that element, forming
carbonic oxide and an equal volume of hydrogen, so also
when steam acts upon a compound of carbon and hydrogen,
it produces carbonic oxide, but in doing so sets at liberty
not only its own hydrogen but that of the carbohydrogen
also ; and thus the volumes of hydrogen and carbonic oxide
remain no longer equal, but the volume of the former becomes
double, treble, or even fourfold that of the latter. Thus the
non-luminous gases contain a very large proportion of hydro-
gen, which, as we have already proved, is very much prefer-
able to carbonic oxide and light carburetted hydrogen, on
account of the relatively small extent to which a given volume
vitiates the atmosphere and heats the apartments in which it
is consumed.

It has been supposed that the gases generated by the new
process have, to some extent, the nature of naphthalized
gases, and that, therefore, when allowed to stand for some
time in the holder, and especially when exposed to a freezing
temperature, their illuminating power would be much dete-
riorated. It was of importance carefully to ascertain the
value of this objection, and I therefore allowed a specimen
of the Boghead hydrocarbon gas to stand over water in a
holder for forty-eight hours, but at the expiration of that
time, its illuminating power had not suflfered the least dete-
rioration. I then exposed various specimens of gas to the
temperature of melting ice for several hours ; the usual mode
of doing this, by allowing the gas to stream through a ser-
pentine pipe surrounded by ice, is nearly valueless, since the

OF THE MANUFACTURE OF OAS.

118

temperature of the gas does not become reduced to 32° unless
the tube be inconveniently long and the stream very slow;
and if any hydrocarbons are condensed, they have not time
entirely to deposit, but a portion is carried forward in the
vesicular condition, until on emerging from the refrigerator
it is again gasified by the increasing temperature. To avoid
these errors an apparatus* was employed in the following
experiments, by means of which the volume of the gas satu-
rated with watery vapour, and at the temperature of about
60°F., could be accurately ascertained, and the gas then trans-
ferred without loss into the refrigerator, where it was exposed
to 32'^ for not less than one hour; it was then transferred
into the measuring portion of the apparatus, the pressure
upon the gas being constantly preserved equal to that of the
external atmosphere; when the gas had again become perfectly
saturated with watery vapour, its volume at 60°F. was again
ascertained ; the difference gave the loss of hydrocarbons in
the refrigerator. I have not submitted all the gases to this
test ; but it has been applied to a sufficient number to show
that those made by the new process, so far from losing more
illuminating materials by exposure to cold, lose in all cases
less than the corresponding gas made by the usual process
from coal alone.

The following are the results of these experiments : —

NAME OF GAS.

Cubic feet of hydrocarbons
condensed from 100 cubic
feet of gas on exposure to
a cold of 32" p.

Boghead

" with water-gas
Methyl

" with water-gas
Ince Hall

4.42 cubic feet,
.24 "
.33 «
.07 "
.37 "

* This apparatus will be fiilly described along with the one used for the
analysis of the gases.

Q

114

CONTRIBUTIONS TO THE KNOWLEDGE

There is little doubt that all descriptions of coal gas expe-
rience some loss of illuminating principles on exposure to a
cold of 32°, but the gases richest in hydrocarbons will lose
generally the largest proportion ; and hence the advantage of
diluting such gases so as to afford more space for the vapours
of these hydrocarbons, and thus prevent their condensation.
This advantage is seen most strikingly in the behaviour of
Boghead gas, with and without water gas, when exposed to
the ice test. The difference in the case of Lesmahago would
probably be still more striking, as, from the much greater
density of its hydrocarbons, it might be expected to lose a
large proportion when submitted to the ice test in its pure
state.

For the purpose of comparison with the above experi-
ments, I have analysed the gases supplied to consumers from
the Manchester Corporation works, and by several of the
London companies. The specimens were all collected by
myself ; that of the Manchester gas in June, and those of the
London gases on the 15th of July, 1851. In some instances
they were taken from the burner of the consumer, in others
at the works. At the offices of two of the London com-
panies I was kindly permitted to take the illuminating power
of the gas by means of a Bunsen's photometer ; the illumi-
nating power of the other gases is deduced from the analytical
results.

I have assumed that the sperm candles used in the experi-
ments just alluded to were burning 130 grs. of sperm per
hour, and have corrected the observations to the standard of
120 grs. per hour. For obvious reasons, I omit the names of
the companies by whom the various gases were supplied.

The following are the numbers obtained : —

OF THE MANUFACTUBE OF GAS.

116

5.3 i

5 o o

t>. — '

l-H t>.

IS"

'is

•g-1

tS"!

--< 00 — 4

O -H

t» ^ ,^ rt

JO 1-1

15

h O h U fci o

d V d 7 «e

» -*

•a "3 "3
« o p

goo

o 5 .2

»

116

CONTRIBUTIONS TO THE KNOWLEDGE

The per centage amount of olefiant gas contained in the
Pelton gas and the gases marked B and C in the above table,
all of them coal gases, would lead us to infer that their illu-
minating power is much lower than is really the case, for
according to the experiments upon cannel gases, it appears
that when a consumption of 5 feet per hour produces a light
equal to 20 candles, the gas contains 13.12 per cent, of
olefiant gas, or its equivalent in richer hydrocarbons; and,
hence, we should expect that a gas containing only half this
amount would, when burnt at the same rate, produce a light
equal only to 10 candles, instead of 13, as is found to be the
case. This excess of illuminating power in the case of coal
gases over that indicated by analysis, is probably owing to
the presence of luminiferous constituents not condensible
either by fuming sulphuric acid, or by chlorine. The nature
of these constituents, and the cause why they cannot be
detected by our present methods of gas analysis, I have
already pointed out, (Journal of Chemical Society, vol. iii.
p. 42.) The following table exhibits this difference between
the value of olefiant gas in coal gas, compared with that in
cannel gas, and shows also, that in the case of the latter
the illuminating power is always directly proportional to the
amount of olefiant gas to which the per centage of condensible
hydrocarbons is equivalent. The establishment of this rule
with regard to gases having such different per centages of
light carburetted hydrogen as the Boghead gas, with and
without water gas, I hold to be conclusive evidence that light
carburetted hydrogen has no higher illuminating power than
hydrogen or carbonic oxide*

Value of 1 cubic foot of the olefiant gas, contained in the
following gases, expressed in sperm candles, each burning
10 hours, at the rate of 120 grs. per hour.

OF THE MANUFACTURE OF GAS.

117

CANNEL GASES.

Inoe Hall oannel 2.95 candles^

Ditto with water gas 2.96 "

Boghead cannel 2.80 "

Ditto with water gas 2.83 "

Lesmahago cannel 2.58 "

Ditto with water gas 2.54 "

Ramsay's Newcastle cannel , 2.88 "

Ditto with water gas 2.86 "

Methyl cannel 3.04 "

Ditto with water gas 3.03 "

COAL GASES.

Pelton coal 4.23 candles.

Gas B 3.73 "

Gas C....... 3.91 «

The conclusion resulting from the application of Mr*
White's hydrocarbon process to coals and cannels may he
thus summed up : —

1. It greatly increases the produce in gas from a given
weight of coal or cannel, the increase being from 46 to 290
per cent, according to the nature of the material operated
upon.

2. It greatly increases the total illuminating power afforded
by a given weight of coal, the increase amounting to from
12 to 108 per cent.^ being greatest when coals affording
highly illuminating gases are used.

3. It diminishes the quantity of tar formed, by converting
a portion of it into gases possessing a considerable illumi-
nating power.

4. It enables us profitably to reduce the illuminating
power of the gases produced from such materials as Boghead
and Lesmahago cannels, &c., so as to fit them for burning
without smoke and loss of light.

5. It increases the per centage amount of hydrogen and

118

CONTRIBUTIONS TO THE KNOWLEDGE

diminishes that of light carburetted hydrogen, thus decreasing
the vitiating effect upon the atmosphere and the oppressive
heat of the apartments in which the gas is consumed.

6. In addition to these positive advantages, the use of this
process does not incur any additional expense in the working
of the apparatus, or the wear and tear of retorts ; it involves
no alterations in the construction of furnaces and apparatus
at present employed in gas manufactories conducted on the
old system.

TABLE SHEWING THE QUANTITY OF COAL OR CANNEL RE-
QUISITE FOR PRODUCING LIGHT EQUAL TO 1000 SPERM
CANDLES, EACH BURNING 10 HOURS, AT THE RATE OF 120
GRS. PER HOUR.

Name of CoaL

Wigan cannel (Ince Hall)
Wigan cannel (Balcarres)

Boghead cannel

Lesmahago cannel

Newcastle cannel . .

Newcastle coal (Pelton)
Methyl cannel

Weight of Coal.

By old process.

By

White's process.

465.1 lbs.

347.4 lbs.

539.0 •'

378.4 "

197.5 "

104.8 "

293.9 "

160.7 "

443.9 "

396.7 «

745.7 "

421.4 "

202.0 "

OP THE MANUFACTURE OF GAS.

119

H
zn

<
O

PR

.9 s

.S!3

0 O •

31

1^
1-^

eo CI CO C-l (M

Oj »C CI <o OO O

r^ CI ^ /-I

F-t o o) CO

CO CO CO
CO w o>

r-H U5 -*
00^ ^ CO^
-^ -«ir r-T

rt »o ,-<

,-1 ^ CO

CO d 00

r-<^ -«J<_ O^

r-^ oT «r «r

«5 (M <M "-I

121

VI. — Notes on the Drift Deposits found near Blackpool.
By E. W. BiNNEY.

[Read February 24(h, 1852.]

In a communication to the Manchester Geological Society*
made by the author in 1842, and printed by that society in
its annual Report, a general description of the Lancashire
and Cheshire drift deposits was given. It was there stated
that few organic remains had been found in the deposits lying
east of a line drawn from Preston to Congleton. In another
paper printed in vol. viii. (new series) of this Society's
Transactions, p. 204, he describes the drift found in and
near Manchester at some length ; but he makes no mention
of the occurrence of fossil shells, none in fact having been
met with by him in the beds alluded to. This diiFerence in
the distribution of organic remains in the drift is a subject
well worthy of attention. It does not appear to be owing to
the mechanical characters of the deposit ; for while no shells
have been met with in the sands and fine gravels of Kersal
Moor, near Manchester, similar deposits at Bowdon afford
them in considerable abundance. The till of Manchester, so
far as it has at present been examined, is also destitute of
fossil shells, while the same deposit in most places west of a
line drawn from Preston to Runcorn yields them more or
less.

We should scarcely expect to find delicate and fragile
shells in a coarse gravel. If the mechanical characters of the
deposits would account for the difference in preservation of
the organic remains, the matter would be comparatively easy;

• Report of the Manchester Geological Society for 1843, p. 15.

R

122

NOTES ON THE DBIPT DEPOSITS

but as we find that the sandy, gravelly, and clayey strata of
the deposits have little to do with the occurrence of the fossils,
probably the beds on and near the flanks of the Pennine
chain may have been formed under conditions in some way
less favourable to organic life, or else the shells of the
mollusks of the then existing shells have been more fre-
quently destroyed than those deposits more remote and lying
near the present sea.*

Few places in Lancashire present greater facilities for study-
ing the drift deposits, especially that part of them known by
the name of the " Till," than the cliffs lying between Black-
pool and Rossall, but up to this time little information upon
them has been given to the public.

At p. 127 of the Rev. William Thornber's " History of
Blackpool" is the following note, where that author, speaking
of what he calls "that immense congeries of diluvium," states,
" This marly deposit has never been perforated, the late
attempt to find coal at Poulton Breck having failed, after
boring 179 yards through marl commixed with gypsum,
intersected at times with loamy sand and gravel." f This
description is somewhat confused, but the beds of gypsum
give pretty good evidence that other strata than those of
the drift, or as the writer terms it, the diluvium, were
penetrated. The beds of marl, loamy sand, and gravel,
would appear to shew that the till and lower gravel had
been met with, but, as gypsum is mentioned, it clearly
shews that either the upper red marls of the trias, or
the lower red marls of the permian, similar to those lying
above the magnesian limestone, and below the upper new

* Since this paper was written, Mr. J. F. Bateman, Mem. Inst. C.E., F.G.S.,
has informed me that in making the Ilollingwortli reservoir, near Mottram in
Longdendale, he met with the common cockspur sliell (Turrittella terelra) in
considerable abundance. This place is about 450 feet above the level of the Irish
sea, in a deep gorge running from the Pennine chain.

+ Man dialer Guardian, October, 1848.

FOUND NEAR BLACKPOOL.

123

red sandstone at Barrow Mouth near Whitehaven, had been
reached under them ; so the result of the boring cannot be
depended upon as giving any correct idea of the thickness of
the drift at or near Poulton Breck.

In speaking of these deposits, my observations will relate to
the higher ground lying to the north of Blackpool, and not to
the low peaty district lying to the south of that town.

The whole of the country appears to consist of the following
beds, in a descending order, namely : — *

1st. A bed of brown clay, mixed with stones,
used in brick-making, of about 4ft. to 5ft.

2nd. A brownish coloured clay, containing stones and
so many pieces of limestone as to render it unfit for the
purpose of making bricks. It is called " good till" in
the neighbourhood. The clay is often replaced by stra-
tified beds of sand and gravel 80ft.

3rd. A bed of silt of a liglitish brown colour, contain-
ing a few pebbles, of about 2ft.

4th. Brownish coloured till,' mixed with stones to the
extent of nearly one-third of its whole mass, exposed ...30ft.

From the above it will, at once, appear that the drift depo-
sits here are of a much simpler composition than the beds
found near Manchester, and fully tabulated at p. 204 of the
second paper before alluded to.f This probably may arise
from some of the upper beds having been removed, and the
inferior ones not being now exposed.

The cliflF from Blackpool to Rossall varies in height from
40 to 90 feet, or thereabouts, and has an undulated character.
In some of the hollows found in it are thin beds of peat lying

* The forest sand on the highest part of the cliff in Bispham is not noticed
here, but it lies upon the brick yard clay. When this paper was read the
author took it for a recent sand hill. He has not seen it in any other localities than
this one, but it appears to occupy the same position as the forest sand of Kersal
Moor.

t Vol. viii. (second series) of the Jlcmoirs of the Society, p. 201.

124

NOTES ON THE DRIFT DEPOSITS

t

upon a light coloured silty clay, con-
taining the remains of fresh water
shells. These beds have evidently
been formed in small swamps, by
obstruction to the natural drainage.
The most remarkable of them is that
seen a little south of the Gynn,
where the bed of peat is about 4
feet in thickness. In it are some
hazel nuts, besides oak, birch, hazel,
alder, and willow trees ; but to my
knowledge, up to the present time
no fossil bones or other remains of
animals have been met with in it,
so as to render it worthy of a more
detailed description.

The brownish coloured brick clay,
No. 1, appears to cap the deposits
the whole of the distance lying be-
tween Blackpool and North Fell,
whether they consist of clay or sand
and gravel.

The cliiT at Blackpool, for the
distance of about a mile, consists of
clay and silt, with some isolated
patches of stratified sand and gravel.
Then comes about a mile and a half
of stratified sand and gravel. The
remainder of the distance to Rossall
is composed of clay, with beds of
silt at North Fell. See wood-cut,
which, although on an exaggerated
scale, will give some idea of the
section.*

* The beds of sand and gravel dip much more in the wood-cut than when see
in the natural section, where they appear almost level.

FOUND NEAR BLACKPOOL.

125

The order of super-position of the beds is not at all easy to
make out, as there are such intercalations and graduations of
one into another that at times it is impossible to speak with
any degree of certainty.

Under the Royal Edward Hotel and at North Fell are
beds of silt, forming arches dipping north and south, thus
plainly shewing that this deposit has been subjected to consi-
derable movements since its deposition. North of the Gynn
the stratified beds of sand and gravel have a slight tendency
to dip towards the south. Further on, in Bispham, the beds
of gravel have been cemented together so as to form a hard
conglomerate, which is much used in making rockeries and
walls at Blackpool. Near the highest part of the cliff, a little
south of the first farm house past the Gynn, No. 1 bed is
capped with several yards of brownish coloured forest sand.

Having given the above general sketch, I shall now pro-
ceed to describe the several beds a little more in detail : —

No. I deposit much resembles the till in the neighbourhood
of Manchester, except that it is of a rather browner colour,
and effervesces more strongly when treated with acids. The
upper portion of it, from its freedom from stones, is well
adapted for brick-making, but after going down four or five
feet, it contains many small fragments of limestone, and
becomes more stony, and, consequently, unsuited for such
purpose, although it makes good " till"* for the land, as the
brick-makers say. In the brick-yard, near to the railway
station, I found fragments of shells, but they are not very
plentiful.

Upon carefully examining 100 specimens of the rocks thrown
out of the clay by the workmen who were employed in digging
it for brick-making, I found them as follows : —

* The origin of the term Till, in geology, no doubt arises from that deposit
having been used by farmers as till for their land when it was marled.

126

NOTES ON TIJE DRIFT DEPOSITS

Partly

Angitiar.

rounded.

Rounded,

17

20

12

5

16

11

3

2

1

4

3

2

Total.

Granites, greenstones, porphyries, &c. 49

Slates and Silurians 32

Mountain limestones 6

Ck>al measures 9

New red sandstones and other sujie-

rior rocks 4 12 1

100 30 43 27

Six of the slate and silurian specimens were striated.

In the brick-yard near to the Royal Edward, on examina-
tion of 100 specimens, I found that the stones there thrown
out of the clay were of the following descriptions, viz : —

Granites, greenstones, porphyries, &c 42

Slates and Silurians 44

Mountain limestones 4

Coal measures 8

New red sandstones and other superior rocks 2

100

Their external characters were pretty much the same as in
the table above described, of specimens from the brick-yard
near to the railway station. Similar fragments of shells were
likewise met with.

Deposit No. 2 is shewn on the face of the cliff under the
bed last described. The clay to the deptli of about 15 yards
in some places is without much change of character, except
that it is a little more stony. Isolated patches of stratified
sand are met with in it. One or two of these may be seen in
the face of the cliff below the Royal Edward, and by their
soft nature cause the cliff to fall faster than in other places.
Shells are more frequently met with in it than in the brick
clay. Few marks of stratification can be traced in the deposit
except where the beds of sand and fine gravel occur.

These are regularly stratified, contain numerous shells, and

FOUND NEAR BLACKPOOL.

127

on towards Bispham, where they dip slightly to the south,
appear to occupy the place of the bed of clay last described.
At this place they consist of beds of coarse shingle and fine
gravel, parted by layers of sand, scarcely to be distinguished
from the pebbles found on the present beach at high water
mark. Nearly all the stones are well rounded, and exhibit no
marks of strite. Most of them consist of granites, traps, and
slates, with some few limestones, the softer stones, doubtless^
having been destroyed by the action of water. At the highest
part of the cliff, these beds of gravel are full 60 feet in
thickness.

The greater portion of the shells hereinafter described were
found by me in the deposits of sand and fine gravel near
Bispham. Many of them are in a perfect condition, and shew
every appearance of not having travelled or been conveyed
from a distance. Most probably they lived near the place
where they were found.

Mr. Thomas Glover, of Manchester, who was so kind as to
examine my specimens, recognised the following: —

Univalves.

Nassa reticulata. — Not at the present time common on the Lancashire coast.
Purpura lapiilus. — Common on the rocky shores of North Wales, and ocea-

eionally washed up at Blackpool. ;

Buccinum undalum. — Common at Blackpool.
Fusus Bamfiiis. — Not common on the Lancashire coast.
Roitellaria pes pelecani. — Occasionally washed up at Blackpool.
Triton erinacetis.— Coxavaow at Hilbre Island, and often washed up at Blackpool.
LUtorina rwdw.— Common at Blackpool.
Natica monilifera. — Found at Blackpool.

Nerita liltoralis. — Common on the Lancashire coast on stones and sea weed.
Turritella terelra. — Common at Blackpool.
Dentalium entalis. — Often washed up at Blackpool.

Bivalves.

Venus gallina.—0&.ein occurs at Blackpool.
Mactra subtruncata. — Common at Blackpool.
Mactra solida. — Common on the Lancashire coast.
Cardium edule. — Very common on the sand banks.

128

NOTES ON THE DRIFT DEPOSITS

Cardium aculcatum. — Common at Blackpool.
C'orbula ineguivalvit. — Pound occasionally at Blackpool.
Psammobia solidula. — Very common at Blackpool.
Ostrea edulis. — Often washed up at Blackpool.

Professor Edward Forbes* appears to have examined the
drift deposits in some parts of Lancashire, as he notices the
solen siliqua, mactra lutraria, a dentalium, found near Pres-
ton, and nassa reticulata, as occurring in them, elsewhere.
However, he names no particular localities, except that of
Preston. Doubtless, he did not visit Blackpool cliffs, or his
well practised eye would soon have discovered the specimens
above enumerated, and procured by me from that place.f

No. 3 is a stratified deposit of fine silt of a brownish colour,
containing few stones. It is about two feet in thickness.
Very few shells have, as yet, been found in it by me. The
most remarkable feature which it presents, is its contorted
annearance. In the cliff below the Royal Edward it forms
a complete arch, dipping northwards and southwards ; another
flexure of a similar character, and dipping in like manner, is
seen at North Fell, thus clearly shewing that it has been sub-
ject to considerable movements since its original deposition. J
It is placed upon the brown stony till next described.

* On the connection between the distribution of the existing Fauna and Flora
of the British Isles, and the geological changes which have affected their area,
especially during the epoch of the Northern Drift, by Edward Forbes, F.R.S.,
L.S., G.S., Professor of Botany at King's College. London, vol, i. of the Memoirs
of the Geological Survey of Great Britain, p. 3C7, et seq.

■f* Long after both the writing and reading of this paper, indeed, just before it
went into the printer's hands, I obtained a sight of the Rev. William Thornber's
very interesting historical and discriptive account of Blackpool, published as
far back as 1837. At p. 128 the author says, "After most diligent inquiries
I have never ascertained that any fossil bones, teeth, &c., of animals, terrestrial or
marine, have ever been discovered imbedded in the marl; shells, however, in
every repect similar to those now existing on the shore, namely, hucdnum unda-
tum, pui'pura lapillus, nassa reticulata and macula, murex erinaceus, Jusus anti-
quus, turritella ierebra, liltorina vulgaris, cardium, cohinatum, and edule, tellina
solidula and tenuis, mactra solida and sultruncata, &c., I have taken out of the
cliffs and gravel strata."

J The lilts beds at North Fell are three or four in number. The lowest part of

FOUND NEAR BLACKPOOL.

129

No. 4. — This consists of a brown clay, rather darker in co-
lour than deposits Nos. 1 and 2 before described, and mingled
with many stones stuck into it in all directions, some standing
on their edges, others on their sides, and some again on their
flat surfaces. The rocks are very numerous, and in the lower
part of the cliff, below the Royal Edward, constitute fully
one-third of the whole mass. Their average size is greater
than in any of the other deposits, one specimen, a greenstone,
now lying on the beach, evidently derived from this deposit,
weighing nearly three tons. More than one-half of the whole
of the stones are angular, others are partly angular, and few
are rounded. Scarcely a slate, or carboniferous rock of six
inches in diameter, can be found without some marks of striaa
upon it. These run nearly always parallel to the major axis
of the stone. The hard greenstones and porphyries do not so
frequently shew striae as the other specimens do. The kind
of rocks found in this deposit is difficult to get at by counting
in the cliff, but 100 specimens each of which was not less than
the size of my fist, taken promiscuously from the shingle lying
on the beach below, and which had, beyond doubt, been
derived from the cliff, were as follows : —

New red sandstone 1

Carboniferous series— 10 limestones and 4 gritstones 14

Silurians and slates 49

Granites, greenstones, porphyries, &c 36

In the till found in the neighbourhood of Manchester, spe-
cimens of magnesian limestone and new red sandstone are met
with. At Blackpool, in that deposit I have not yet met with
a specimen of the former rock, but many of the latter, and
one of the permian conglomerate, have been found. An inte-

the bed of clay No. 2, just above the bed of silt at the south end of the arch
below the Royal Edward, is, for the thickness of about 10 inches, quite paved
with stones, when compared with the average quantity found in the deposit.
The bed of silt appears to form the upper boundary of the stony till next
described, and, like that deposit, is only exposed to a limited extent.

S

130

NOTES ON THE DRIFT DEPOSITS

resting fact is, the quantity of both granular and fibrous
gypsum and waterstone from the upper red marls of the trias.
These I have seldom found previously in the till of Lanca-
shire. But the greatest novelties, in the shape of rocks, are
two specimens of lias, containing the gryphaea incurva and
pieces of chalk flint. These I have never yet found in Lan-
cashire, except at Blackpool, nor have I ever heard of their
having been noticed by other parties.

The shells met with in this deposit are, on the whole, much
more numerous than those found in Nos. 1 and 2, but they
are nearly all more or less broken. I have found specimens
of the genera turritella, nassa, buccinum, dentalium, nucula,
cardium, tellina, and psammobia, most of which had been
previously found by my friend, Mr. Robert Harkness, in the
till, near Ormskirk.

The sea appears to be encroaching on the cliff composed of
till, where it is not protected, at the rate of about one yard
every year on the average. At places where the sand and
gravel beds occur, its attacks are more rapid. This destruc-
tion of the land seems to have gone on for centuries, as the
low water mark, at spring tides, shows numerous large blocks
of stone, evidently derived from the till and gravel, when the
boundary of the cliff was nearly at that point. Some of the
pieces of cemented gravel, like the Pennystone, are of im-
mense size.

During the last year, the beds of sand and fine gravel (No. 2)
in the cliff between the Royal Edward and Dickson's Hotel,
have been exposed far more than they had been previously
supposed to exist in that neighbourhood ; and if the sea is
allowed to continue its attacks, without any attempt being
made to resist it, the destruction of land will, most probably,
be much greater than at the rate at which it has been destroyed
during the last ten years.

As previously stated, the deposit. No. 2, in Bispham, bears
every resemblance to an old beach of shingle, like those at

irotND NKAB BLACKPOOL.

131

present forming on the shore below, but the till No. 4 pre-
sents a very different appearance, and bears no analogy to any-
thing now in the course of formation along the line of the
neighbouring coast. The angular and striated characters of
the rocks mingled together promiscuously, large and small,
without any arrangement, some upon their edges, others in-
clined, and some again quite flat, must puzzle any observer to
account for them by the action of waves or ordinary currents
of water. Upon comparing them with the stones now found
lying upon the beach below, it is quite evident that the rocks
are of the same kind, and that all the latter have been derived
from the cliflTs; but the action of waves, during years, has evi-
dently worn away the sharp edges, and defaced the striae from
most of the specimens. Few persons, however, are at all
aware how short a space of time suffices to round the most
sharp-edged piece of hard greenstone, washed out of the cliff
and subjected to the action of the waves below. A mass of
till full of angular stones being undermined by the sea,
falls, the clay is soon washed away, and the stones are thus
brought within the action of the water, and, in one short
month, the waves have so effectually done their work of attri-
tion that the roc*ks are as round as if they had been rolled
about for years.

An opinion expressed by me, in a paper on drift deposits
previously referred to, as to the till of Lancashire having been
deposited at the bottom of a sea in which floated numerous
icebergs, I am more and more confirmed in. However the
beds of sand and shingle found above the till may answer to
the term "raised beach," the till itself bears no evidence of any
such condition, but ought rather to be termed a raised bottom.
It has thus been affected by considerable movements since its
deposition, and much twisted and contorted, as numerous sec-
tions of it and the silt sufficiently prove. Many parts of it
appear to have been subjected to much erosion and denuda-
tion prior to the deposition of the beds "now covering it. Most

132

NOTES ON THE DRIFT DEPOSITS

of the hard rocks in the beds of gravel are of the same kinds
as those found in the till, however much their external cha-
racters may have been altered. In all probability, therefore,
the former is merely the debris of the latter.

On the upraising of the till from the bottom of the sea, its
surface would soon become liable to the abrading action of
the waves, and thus furnish rocks for the sands brought by
currents from the neighbouring new red sandstone coast, just
as the present clifis furnish the pebbles for the shingle beaches
at Blackpool.

The rocks in the till have, no doubt, come from a consider-
able distance, especially the lias and chalk specimens, which
are not now found in situ nearer than the north-east coast
of Ireland.

The rocks in the till at Manchester, taken on three diflfer-
ent sides of that town, gave mean results as follows :* —

Partly

Total. Angular. Rounded. Rounded.
Granites, greenstones, and other

igneous rocks 21 5 10 6

Slates and Silurians 21 3.66 9 8.33

Mountain limestones 6 13 2

Coal measures 49.33 25.33 19 5

New red sandstones 2.66 2 • 0.66 0

Striated rocks 1.66

In the brick-yard near the railway station at Blackpool,
the rocks were as follows : —

Partly
Total. Angular, Rounded. Rounded.
Granites, greenstones, and other

igneous rocks 49 17 20 12

Slates and Silurians 32 5 16 11

Mountain limestones ..<■ 6 3 2 1

Coal measures 9 4 3 1

New red sandstone and superior

rocks 4 12 1

Striated rocks 6 slates and Silurians.

♦ Memoirs of the Lit. and Phil. Society of Manchester, vol. viii. (new series)
p. 224.

FOUND NEAB BLACKPOOL. 133

The above tables shew that the surface till of Manchester
differs from that of Blackpool in having a much smaller pro-
portion of granites, igneous rocks, slates, silurians, and striated
stones, and a much greater proportion of coal measure rocks.
This, as might have been expected, if we assume a force
moving, from the north-west to the south-east, for one-half the
distance between Blackpool and Manchester, as may be seen
by looking at a geological map, is over the great Lancashire
coal-field. The two rival theories put forth to account for the
phenomena found in the till, namely, the iceberg and wave of
translation, or a combination of them both, might each account
for the difference; but the beds of stratified silt, both at
Manchester and Blackpool, present appearances which no
wave of translation can account for, as they must have been
deposited in moderately still water. The striated and polished
surfaces of the stones seem to indicate the action of glaciers,
or rubbing of a mass of ground ice over a rocky bottom.

The lower bed of till, composed nearly of one-third its bulk
of stones, presents appearances such as are not seen in the
upper beds either at Manchester or Blackpool, for the majo-
rity of the rocks found in it bear marks of strias, or have
polished surfaces. Some of them are stuck into the clay right
on their edges, and others at every variety of angle. Although
the rocks here are far more numerous than in the till at
Manchester, or in any of the beds superior to the silt at
Blackpool, still I have met with more large specimens, say
those exceeding two tons, at the former place than at Black-
pool.

With the exception of the lias and chalk specimens, the
coasts of Cumberland and Furness could supply nearly all the
rocks now found in the deposit. But how have they been
carried to the place where they are now met with, scored,
polished, angular, partly rounded, and placed on end, as they
now are ? Their present conditions seem to require the con-
joint action of glaciers and icebergs to produce them. Now

134

NOTES ON THE DBIFT DEPOSITS

let us suppose a glacier filling the deep valley of the Duddon,
or any of the other valleys of Cumberland, and extending
from the mountain sides down into the sea, until part of it
broke off and floated away across Morecambe Bay as an ice-
berg, (a circumstance of common occurrence with the glaciers
of Spitzbergen and other northern countries,) and afterwards
melted or toppled over, having deposited its cargo of rocks and
debris on the bottom of a sea composed of soft mud. This
would account for most of the phenomena we witness in the
till. The Scotch and Irish rocks might have been brought by
a stray iceberg conveying specimens of stones from those more
remote districts. I mention this opinion, formed after a care-
ful consideration of the appearances observed in examining
the bed of stony till, but, of course, it will not account for the
sand and shingle beds, which are evidently nothing more than
old littoral deposits. The beds of clay, containing pebbles
Nos. 1 and 2, do not afford such strong proofs of glacial and
iceberg action as deposit No. 4, but still they exhibit more
appearances of having been deposited at the bottom of a sea
in which icebergs floated than under any other condition.

The deposit No. 4 is by far the greatest in thickness,
although very little of it is exposed at Blackpool or North
Fell under the beds of silt, which I think might be termed
its upper boundary.

The two anticlinal axes of the bed of silt lead me to suppose
that the deposits Nos. 1 and 2 lie in a synclinal axis of it,
which extends from near the Gynn to North Fell. The dip
of the beds of gravel may scarcely bear out this view, but that
is by no means so great as appears in the section, as I previ-
ously stated ; in fact, in some places it takes a northerly dip,
and at others is so small as scarcely to be appreciated ; so I
have little doubt of the beds of silt and stony till underlying
the whole of the gravel between the two last named places.
It appears to me the till was once an old sea bottom. Upon
its being elevated, it would soon be exposed to the action of

FOUND NEAR BLACKPOOL. 136

currents of water, and much eroded and washed away. In
the hollows caused by such agencies, the littoral deposits
of sand and gravel may have been deposited. The land
then appears to have subsided and icebergs and glaciers
again come into operation, although to a less extent than
on the first occasion before alluded to, as the number
of rocks, and especially such as are scored and striated, is far
less than those met with in No. 4. Subsequently, the whole
district has been elevated from the sea into its present
position.

The more that the phenomena of the drift deposits are
studied, the more we must be convinced that so far from
having been formed in a short period of time, as was once
the generally received opinion, when they were erroneously
attributed to the Noachian deluge, they have occupied
ages in their formation ; during which, they have been
more than once raised and depressed, and considerable por-
tions of them washed away and replaced by other deposits.
These changes of level, there appears to be no reason for
believing were of a more speedy nature than the slow and
gradual motions of the land we see going forward upon the
face of the globe at the present time. The sands and gravels
of the deposits are easily recognised as ancient strands and
beaches; but the beds of till present us with no such
appearances, presenting every indication of having been once
the bottoms of ancient seas, in which floated various
rocks freighted with numerous icebergs, which, on being
dissolved or toppled over, deposited their loads on the soft
mud below.

137

VII. — Some account of the Floods which occurred at the
Manchester Waterworks in the month of February, 185^.

By John Frederic Bateman, F.G.S., Mem. Inst. C.E.

[Read March 23rd, 1852.]

In the year 1848, in giving to the society a continuation of
the periodical reports upon the fall of rain, the Valley of
Longdendale, from which the town of Manchester is to be
supplied with water, was shortly described, and such obser-
vations as had at that time been made upon the rain in the
district, and the quantity of water which flowed from the
ground, also accompanied the paper.

Since that period most of the observations upon the fall
of rain have been continued, and the vast works for the
storage and conveyance of water which were then only in
contemplation have been in great measure executed, and are
now rapidly advancing towards completion.

In the main valley of the Longdendale district, down which
flows the river Etherow, three large reservoirs are now con-
structing, filling the valley for nearly five miles in length.
These three reservoirs will contain, when finished, about
516,000,000 cubic feet of water, and will cover about 344
statute acres of ground. The Woodhead Reservoir, which
is the highest of the series, is formed by an embankment of
90 feet; it is about a mile and two-thirds in length, and
receives the water naturally draining from about 7,500 acres
of high mountain land. The Torside Reservoir, the middle
one and the largest of the three, with an embankment of 100
feet in height, and the Rhodes Wood Reservoir, immediately

T

138

FLOODS AT THE MAKCHESTEE WATERWORKS

below, with an 80 feet bank, have together an additional
collecting ground of about 7,900 acres, making the total
drainage to these three reservoirs 15,400 statute acres. The
Torside Reservoir is nearly two miles in length, and the
Rhodes Wood Reservoir about a mile.

The following are some particulars of the reservoirs : —

Embankment.

Resekvoie.

RXSKBTOn.

QreatesI
height.

Contents.

Area.

Capacity.

Woodhead

Ti-it.
90

100

81)

Cubic Yards.
152,707

399,129

263,248

A. R,

134 3

160 0
54 0

p,
18

6

34

Cubic Feet.
198 725 693

Torside

236,659,573
80 255,910

Rhodee Wood

815,084

349 0

18

515,641,176

In the execution of works of this magnitude, placed across
a valley down which the ordinary water and impetuous floods
of so large a tract of mountain land are hurried with rapidity,
it is very important to provide ample means for the safe pas-
sage of the water. Observations had accordingly been made
with reference to this particular object for some jears pre-
vious to the laying out of the works. From these observa-
tions it appeared that it was not likely that many floods
would exceed 10 feet per second for every 100 acres of
collecting ground, and that provision for 15 feet per second
would be ample. The ■ Woodhead Reservoir was the first
which was laid out for construction, and in designing the side
channels or watercourses for carrying away the floods during
the early progress of the embankment across the river course,
they were formed of such dimensions as would, with the
assistance of a large discharge pipe under the embankment,
pass off" safely about 1,000 cubic feet of water per second,
being at the rate of about 15 feet per second for every 100
acres.

IN THE MONTH OF FEBRUARY, 1852. 189

The ground was first broken for the construction of this
reservoir in September, 1848 ; and, in the following month,
before much progress had been made, a very heavy flood
occurred in the neighbourhood of Blackburn, which was the
cause of a lamentable accident at Darv^^en, near that town, by
the bursting of a private reservoir and the consequent loss of
twelve or thirteen lives. The volume of this flood I was
enabled to determine with tolerable approximation to accu-
racy, by means of the reservoirs of the Blackburn waterworks,
which were then just completed. It exceeded 25 feet per
second for every 100 acres of collecting ground. Had a
similar heavy fall of rain occurred in the upper part of the
Longdendale district, it would have produced a flood of about
2,000 cubic feet per second at the Woodhead Reservoir, —
nearly double the volume which had been provided for.

Acting upon the experience and information thus acquired,
an additional discharge pipe was immediately introduced, and
the flood watercourse was enlarged as far as practicable, so
that a flood of 1,500 feet per second could be passed with
safety, with 16 feet of pressure upon the pipes. As the em-
bankment gradually exceeded that height in the course of
construction, the means of storage behind the banks would be
increased ; and by the greater pressure upon the pipes more
water also could be discharged, and in these ways provision
would be made for the safe passage of a still larger quantity.
On several occasions, in the course of the following eight or
ten months, the floods amounted to 1,800 or 2,000 feet per
second ; shewing the wisdom, and indeed the necessity of
such a provision having been made.

Early in October, 1849, just twelve months after the
Blackburn flood, which bad aflcirded such valuable information,
the flood watercourse having been completed, the discharge
pipes laid, and every arrangement made for proceeding with
the embankment of the reservoir, the inner tie of that bank
was raised to a height of about 16 feot, so as to give that

14K)

FLOODS AT THE MANCHESTER WATERWORKS

amount of pressure on the discharge pipes in case of neces-
sity. On the 7th a very heavy fall of rain, accompanied with
a hurricane from the north-east, occasioned a flood which set
at nought all previous calculations. When at its highest it
amounted to upwards of 4,000 cubic feet per second, being
at the rate of upwards of 50 feet per second for every 100
acres. After attaining this height, it flowed for the following
three hours at an average of 1,800 feet per second. A weir
on the watercourse across the Heyden Brook, which was not
quite finished, but which had been considered sufficiently so
to secure the safe passage of the water, was absolutely beaten
down by the force of wind and water, and a breach being
made through which the water passed, the watercourse was
thus rendered useless. The water poured into the basin of
the reservoir, and speedily overtopped the newly-formed piece
of embankment. It had been raised to a height of 24 feet,
and was raised 3 feet more during the progress of the flood,
so that when the water reached the top it was 27 feet high.
The bank was not long in being cut down, and a quantity of
water amounting to about 14,000,000 cubic feet was set at
once at liberty. For a short distance it carried all before it,
and did more or less damage for four or five miles down the
river. No serious mischief, however, was sustained, and
happily no lives were lost. The quantity of water which was
impounded at the time of the accident was about equal to
that contained in the unfortunate Bilbury Reservoir, near
Holmfirth, which burst on the 5th of February and did
such fearful injury in the valley below. The difference in
the circumstances of the two cases easily accounts for the
difference in the two results. The depth of the water in the
Bilbury Reservoir was about 80 feet ; at Woodhead it was
27 feet only. The embankment of the Bilbury Reservoir,
owing to its peculiar construction, gave way in a great mass
at once, and the valley into which this mighty wall of waters
was instantaneously hurled is a steep and narrow ravine, down

IN THE MONTH OF FEBKUARY, 1852. 141

which the water would continue to flow with impetuous
velocity. The Woodhead valley, on the contrary, has a much
more gentle slope, and is much wider throughout, occasion-
ally expanding into level flats of considerable width. Con-
sequently the velocity of the water would be speedily dimi-
nished, and its volume absorbed by filling up the flat ground
on each side. The damage was comparatively trifling, being
all repaired or compensated for by the payment of little more
than £:^,000.

The embankment was restored, and no further flood of any
consequence occurred until the work was far advanced. The
remaining reservoirs in the valley had been some time pre-
viously laid out and commenced, and abundant provision had
been made at these new reservoirs for the passage of the
floods.

Of the various rain gauges which are placed in the district,
one only is registered daily, viz., that at Crowden Hall, the
others being placed on the heights in somewhat inaccessible
situations, and only observed weekly or monthly. The quan-
tity of water which was received into the Woodhead Reservoir,
or passed by the flood watercourse on the occasion of the
flood alluded to, must have exceeded 3 inches in the 24 hours,
or rather, in the 17 or 18 hours during which the rain fell
most heavily, and yet the depth registered at Crowden Hall
was only l^i^^inch. Crowden Hall is about two-thirds of a
mile below the Woodhead embankment, and the heaviest
portion of the rain must therefore have been on the hills
above the reservoir. At the Redmires Reservoir of the
Sheffield Waterworks, on the same day, there were registered
nearly 2^ inches. The distance from Woodhead, in a direct
line south-east, is 13§ miles.

The fall of rain in 1849 was about an average, there being
at Crowden Hall 54-i4 inches : 1850 was considerably below
the average, the rain being only 44-^^; and singularly
enough, almost the only heavy flood which occurred in the

U2

FLOODS AT THE MANCHESTER WATERWORKS

course of the year was on the 7th and 8th October, the
anniversary of the destructive flood of the previous year, and
(within a few daj^s) of the Blackburn flood of 1848.

The year 1851 was still more below the average, the rain at
Crowden being only 40^ inches. In this year the only
heavy flood occurred about the 8th and 9th June.

The fall of rain, as registered at the various rain gauges
in the district since the end of 1847, up to which time they
are recorded in my last paper to the Society, is as fol-
lows :• —

1848.

Brushes,
480 ft.

Windy ate

Edge.

1,700 ft.

Crowden

Hall,

700 ft.

Kakes

Moss,

1,620 ft.

Butterley
Moss,
1,750 ft.

Mean of all
the obser-
vations.

Mean,
omitting
Bntshea.

January

February ...
March

Inches.
2.0
8.0
4.7
1.5
1.2
5.3
4.2
5.8
4.2
5.8
2.6
3.6

Inches.

1.7
9.2
4.4
2.1
1.8
6.1
4.2
7.5
5.4
8.3
3.2
3.8

Inches.
1.1
8.2
5.5
2.6
1.0
6.8
4.6
7.0
4.3
8.0
3.1
3.7

Inches.

2.1

7.0
4.4
7.8
5.1
6.0
4.0
2.8

Inches.

1.6
10.1
4.9
2.9
1.0
6.2
2.4
5.8
3.4
7.5
2.3
3.7

Inches.
1.6
8.9
4.9
2.3
1.4
6.3
4.0
6.8
4.5
7.1
3.0
3.5

Inches,

1.5
9.2
4.9
2.6

May

1.5

June

6.5

July

3.9

August

September. . .

October

November....
December....

7.0
4.5
7.5
3.1
3.5

Total

48.9

57.7

55.9

51.8

62.8

55.1

1849.

Brushes,
480 ft.

Wiiidyate

Edge,

1,700 ft.

Crowden

Hall,
700 ft.

Black
Clongh,
1,700 ft

Butterley

Moss,
1,750 ft.

Mean of all
the obser-
vations.

Mean,
omitting
Brushes.

January

February ...
March

Inches.

53

1.5
,6
1.4
3.0
1.8
7.5
4.2
4.8
4.1
4.7
3.8

Inches

6.3

2.4
1.0
2.5
3.4
2.1
8.8
4.5
6.4
6.3
5.8
4.7

Inches.

8.2
2.4
1.5
3.0
2.8
1.7
7.8
5.4
4.7
7.0
5.1
5.1

Inches.
6.0
2.0
2.0
30
2.5
3.0
6.1
4.0
6.3
8.7
4.0
4.6

Inches.

Inches.
6.4
2.1
1.3
2.5
2.9
2.2
7.5
4.5
5.5
6.5
4.9
4.6

Inches.

6.8
2.3
1.5
2.8

2.9

June

2.3

July

7.5

August

September...

October

November,...
December....

4.6
5.8
7.3
5.0
4.8

Total

42.7

54.2

54.7

52.2

50.9

53.6

IN THE MONTH OF FEBRUARY, 1852.

143

1850.

Bmshes,
480 ft.

Windyate

Edee.
1,700 ft.

Crowden

Hall.
700 ft.

Black
Clough,
1,700 ft.

Bntterley

Moss,
17.50 ft.

Mean of all
the obser-
vations.

Mean,

omitting
Brushes.

January

February ...

March

April

laches.

2.9
3.4
0.6
2.4
1.5
1.5
3.7
4.0
1.5
3.6
4.3
2.4

Inches.

4.5
5.0
0.8
35
2.1
2.9
5.5
6.6
2.6
6.4
7.7
2.9

Inches
3.8
4.4
1.1
4.0
2.0
3.4
4.8
3.2
1.8
65
7.8
1.3

Inches.
4.2
4.6
3.5
4.0
1.5
3.5
7.9
5.9
0.7
5.5
7.5
4.0

Inches.

2.8
2.8
0.7
3.0
1.2
2.3
4.1
3.0
1.2
4.0
3.0
3.4

Inches.
3.6
4.0
1.3
3.4
1.7
2.7
6.2
4.5
1.6
6.2
6.1
2.8

Inches.
3.8
4.2
1.5
3.6

May

1.7

June

3.0

July

5.6

August

September...

October

November...
December....

4.7
1.6
6.6
6.5
2.9

Total

31.8

60.5

44.1

52.7

31.5

42.1

44.7

1851.

1 'Wiudyate
Brushes, | Kdge,
480 ft. i 1,700 ft.

Crowden

Hall.
700 ft.

Black
Clough,
1,700 ft.

Butterley
Moss.
1.750 ft.

Mean of all
the obser-
vations.

Mean,
omitting
Brushes.

January

February ...

March

April

Inches.
2.9
2.1
3.6
0.4
1.5
6.8
3.7
4.1
1.8
3.6
1.6
1.5

Inches.
3.1
2.2
3.7
1.5
1.9
6.6
4.6
4.2
1.9
4.6
is
2.3

Inches.
2.5
3.0
4.1
1.8
3.0
6.3
3.8
4.2
3.0
4.9
2.7
0.8

Inches.

3.8
2.5
4.5
2.8
3.5
5.9
1.4
5.3
2.6
4.0
3.2
1.5

Inches.
4.3
2.6
2.9
1.9
3.2
6.0
4.7
3.4
2.5
5.3
1.6
1.4

Inches.
3.3
2.6
3.8
1.7
2.6
6.1
3.6
4.2
2.4
4.6
2.1
1.5

Inches.

3.4
2.8
3.8
2.0

May

June

2.9
6.2

July

3.6

August

September...

October

November...
December ...

4.2
2.5
4.7
2.2
1.5

Total

32.6

38.2

40.1

41.0

39.8

38.3

39.8

Many of the mountain gauges have been stolen, removed,
or tampered with, and I am afraid that the only ones upon
which much dependence can be placed are those at Brushes,
Windyate Edge, and Crowden Hall. When the works are
completed the reservoirs themselves will be the best gauges.

Before giving the particulars of the floods which occurred
in the early part of last month, it will be well to describe the
position of the reservoirs, and the means which they afforded
of ascertaining with accuracy the quantity of water which
was received. It has hitherto seldom or perhaps never hap-

144

FLOODS AT THE MANOHESTEB WATERWORKS

pened that a single heavy flood or fall of rain has been so
accurately observed. This fact is my apology for endeavour-
ing to place the particulars on record.

In the early progress of the formation of the embankments,
provision was made at each reservoir for the passage of
the floods by the construction of a capacious cut or canal
called a flood-watercourse, above the level of the reservoirs,
as already described. This provision was adopted and em-
ployed for the purpose intended both at the Woodhead and
Torside Reservoirs, until the embankments at each place
were advanced to a height at which it was deemed safe to
dispense with the aid of the watercourses, and to depend for
safety upon the storage which the reservoirs afibrded, and the
means of discharge provided by the two lines of 4 feet pipes
which had been introduced in all the embankments. It was
necessary also, as the work advanced, to cut across or destroy
the watercourses for the purpose of completing what are
technically called puddle trenches, which are deep trenches
of retentive material, sunk for the reception of the clay or
puddle employed to render the whole water-tight. The per-
manent waste weirs of the reservoirs also had to be con-
structed on the site of the flood water-channels, for which
purpose likewise they had to be dispensed with.

The Rhodes Wood Reservoir, the lowest of the three,
would have been similarly provided with a bye-channel for
the waste water, but delay had unavoidably arisen by the
channel to be formed over an ancient land-slip. This land-
slip was well known, and had been long moving slowly. At
the turnpike road on the north side of the valley, it had
moved about three feet in thirteen years ; but the speed of
its motion was materially increased on being cut into for the
purpose of forming the watercourse. Means had to be
resorted to for arresting its further progress, and the work
was consequently so much delayed that this watercourse is
not yet completed.

IN THE MONTH OF FEBRUARY, 1852. l4l5

Ample provision, however, for the passage of the floods
at the Rhodes Wood Reservoir was made by leaving a gap
in the embankment, which remained open until the two
higher reservoirs were so far advanced as to be able to hold
all the water which could not be passed through the two
pipes of the Rhodes Wood bank. The gap in this embank-
ment was then closed, and the embankment raised as rapidly
as possible.

This step, however, was not taken, nor indeed any other
which involved the necessity of subsequently depending
upon the power of impounding in the reservoirs for security
against damage by floods, without first considering what depth
of rain could be safely stored in the reservoirs or passed
through the pipes.

Three inches of rain coming off the ground in 24 hours,
with a considerable margin for its continuance or for a heavier
fall, was adopted as the base of our calculations, being con-
sidered as the maximum amount which need be provided for.
This quantity the works were always in a condition to receive
and pass with safety. It was thought, from previous obser-
vation, that it was exceedingly unlikely that a larger fall of
rain than this could occur over the whole district, and it was
expected that should such a fall take place the rain would
then cease, and the reservoirs might be emptied for the recep-
tion of another flood.

Such, then, being the provision which had been made,
and the grounds for believing such provision to be sufiicient,
the position of the reservoirs at the commencement of the
late floods was as follows : —

The Woodhead embankment was raised to its full height,
but it was not deemed prudent to fill the reservoir above a
certain level, in consequence of operations which were going
on to render the hill side into which the embankment had to
be tied perfectly water-tight.

The Torside embankment was far advanced ; but here also

146

FLOODS AT THE MANCHESTER WATERWORKS

operations were being carried on to render the reservoir water-
tight, which rendered it undesirable to impound water to a
greater depth than about 30 feet.

At Rhodes Wood Reservoir, which it will be remembered
is the lowest in the valley, the embankment was sufficiently
advanced to allow water to be impounded 40 feet in depth.
Through the pipes of this reservoir all the water had to be
passed, and therefore by calculating the quantity which could
be discharged through them according as the pressure varied
during the progress of the flood, the whole quantity could
be precisely ascertained.

It is well known that the velocity with which water is dis-
charged through pipes or through apertures, varies as the
square root of the pressure or head of water above the
opening.

The proper co-efficient for finding the mean velocity of the
water discharged varies according to the character of the
opening.

The theoretical velocity due to the height is the same as
that of falling bodies, which is ascertained by multiplying
the square root of the height by the co-efficient 8.0458.

The co-efficient, however, for finding the actual velocity
varies from 5 to 7 ; that generally used for ordinary openings
being from 5.1 to 5.4.

Should the water approach the opening with any velocity,
that must be taken into account, and a higher co-efficient
employed.

To determine the quantity which will be discharged through
pipes, diffi3rent formulae have to be employed, for the friction
along the sides of the pipe forms a material element in
retarding the velocity of the water. Amongst many valuable
rules deduced from the experiments of various eminent
mathematicians and scientific observers, probably the simplest
for calculating this velocity, and perhaps that most generally
adopted, is one by Dr. Young from Eytelwein's Hydraulics,
and is as follows : —

IN THE MONTH OF FEBKUARV 1852. 147

"Multiply 2,500 times the diameter of the pipe in feet by
the height in feet, and divide the product by the length in
feet, added to 50 times the diameter, — then the square root
of the quotient will be the velocity of discharge in feet per
second."

This rule is a tolerably safe one in practice. I believe it
to be under the truth for large pipes and high velocities; and
it requires to be used with judgment in determining the dis-
charge by small pipes, where the system is complex.

The circumstances under which the water was discharged
from the Rhodes Wood Reservoir were so far complicated as
to render the determination of the proper co-efficient a ques-
tion of some difficulty.

Two pipes, each 4 feet in diameter, and 303 and 370 feet
respectively in length, were diminished at the outer end to
3 feet, the vvater being finally passed through a pipe of that
diameter for about 20 feet in length, and through a 3-feet
valve, divided into two compartments. One pipe branched
into two at the end, having a valve at each branch, and
through both of which water was discharged. The pipe is
too large and the circumstances too complex to admit of the
application of the rule for calculating the discharge through
pipes. The water would approach the opening with consi-
derable velocit}', acquired in its passage through the 4-feet
pipe, and therefore, rather a higher co-efficient than that
usually employed for finding the velocity through openings,
should be adopted. From a consideration of all these cir-
cumstances, and from other observations upon the actual
quantity of water discharged, the co-efficient adopted was
5.5 ; and this may be rather lower than it ought to be.

With this co-efficient, however, the calculations came out,
as will be shortly shewn.

The month of January had been marked by a considerable
fall of rain, and at the end of the month the ground was
thoroughly saturated, the streams and springs yielding con-

148

FLOODS AT THE MANCUESTEK WATEKWOEKS

siderably above their ordinary quantity of water. The lieavy
rain which was the cause of so many serious and destructive
floods commenced on the morning of Wednesday the 4th
of February, and, (with slight cessation on Friday and
Saturday,) continued with little intermission till the morning
of Monday the 9th.

On the morning of the 4th the Woodhead Reservoir con-
tained about 24,000,000 cubic feet of water, being about 34
feet deep, and 47 feet below the top water level. The Tor-
side and Rhodes Wood Reservoirs were both empty. Early
in the day the rain had so swollen the streams that the
discharge pipes could no longer pass the water, and it began
to impound rapidly in all the reservoirs. By Thursday night
the water had attained its greatest height, the depth in the
Woodhead Reservoir being about 62 feet, and in the Torside
and Rhodes Wood Reservoirs, about 30 feet. The quantity
impounded was about 103,000,000 cubic feet in the Wood-
head reservoir, 14,000,000 in Torside, and 15,000,000 cubic
feet in Rhodes Wood Reservoir.

From Thursday night the water gradually lowered till
Saturday night, by which time the water had been drawi>
down about 9 feet in the Woodhead Reservoir, and about
5 feet on the average, in each of the others. The quantity
discharged through the pipes of the Rhodes Wood Reservoir
during this period had averaged from 450 to 500 cubic feet
per seconds For 24 hours together, from Wednesday morn-
ing to Thursday morning, the flood had averaged 1,520 cubic
feet per second, being, when at its highest, from 3,600 to
4,000 feet per second. This was from a tract of country, it
will be remembered, of 15,400 statute acres, and amounts to
about 25 cubic feet, per second from every 100 acres of
ground. The ordinary flow of the stream varies from 15 to
30 feet per second. The water which was passed through the
pipes or was impounded in the reservoirs during this period,
wofi equail to a depth over the whole collecting ground of
2x0 inches.

IN THE MONTH OF FECRUAKY, 1852. 14<9

On Saturday night it again commenced raining heavily,
and continued until two o'clock on Sunday afternoon. At
this time the rain ceased for a couple of hours ; but the
streams were swollen to a volume of nearly 3,000 cubic feet
per second, while the utmost that could be discharged through
the pipes of the lUiodes Wood Reservoir was under 600 feet
per second. At four o'clock it again commenced raining with
the same intensity as before, with every appearance of its
continuing through the night. At this moment the prospect
was one of great anxiety. Thousands of persons, alarmed by
the dreadful catastrophe at Holmfirth, had passed up the
valley in the course of the day, in all the pouring rain, to
visit the scene of that calamity ; or had assembled on the
banks of the waterworks reservoirs, anxiously watching the
progress of the flood, and waiting to see the final burst which
the majority anticipated. Towards the evening vehicles of all
kinds, and horsemen at full gallop, despatched by anxious
parties below to make inquiries, were constantly arriving;
and, indeed, to the Engineer confident in the stability of his
work, and in the provision which had been made for the safe
passage of the waters, it was matter of no light concern or
slight responsibility. There remained only six or seven hours
safe storage for such rain as was at that moment falling; after
the expiration of which time, the valves of the Woodhead
Reservoir must have been opened to prevent the further
rise of water in that reservoir, and the water allowed to pass
over the puddle of the Torside bank, through a mass of rock
which had been heaped together in the formation of the bank,
with a view to such a contingency, and over the top of the
Rhodes Wood bank, through a large timber shoot, which had
been hastily but substantially prepared during the progress of
the flood, for the purpose of safely passing the water to the
river below.

In all probability, these preparations would have been
sufficient to have sustained a flood of one or two days

150 FLOODS AT TUB MANCHESTER WATERW0EK3

longer continuance ; but they must have been put to the
test in the middle of the night, in extreme darkness, when it
would have been impossible to have seen what was going on,
or how to meet or remedy any defect which might have
occurred. The work of destruction, at the worst, would have
been very slow and gradual, from the excellent manner in
which the embankment had been formed, and the retentive
and coherent character of the great bulk of the material.
Happily, there was no occasion for the trial. The sun went
down red and glowing with a murky grandeur, dimly seen
beneath the clouds, which, though breaking and clearing
to the west, were then pouring down their contents in
torrents at the place at which we stood. The rain gradually
abated, and nearly ceased before six o'clock, and I was satis-
fied that the worst was over and that all imminent danger was
passed.

Heavy flying showers continued through the night ; but at
day-break the following morning it appeared to be again
setting in for continued rain. The wind up to this time,
during the whole storm, had been blowing steadily from the
south-west, but it now gradually veered round to the north,
and I then felt perfect confidence that the weather was taking
up, notwithstanding the lowering and gloomy appearance of
the morning. The rain subsequently ceased before noon, and
by the end of the week the weather was quite settled and
fine, the barometer gradually rising, and then remaining
steadily fixed at an unusual height.

The water which was impounded in the reservoirs when
the rain ceased on the morning of Monday the 9th, was about
160,000,000 cubic feet, of which nearly 140,000,000 were
due to the rains of the previous week. By noon of the 13th
the whole of this water had been discharged, and the reser-
voirs brought down to the same condition in which they were
on the morning of the ,Srd, when the rain commenced. The
quantity discharged through the pipes of the Rhodes Wood

IN THE MONTH OF FEBRUARY, 1852. 151

Reservoir, through which, as has been before observed, the
whole had to be passed, was as follows : —

Cubic feet.
From nine o'clock on the morning of the 4th to 2 p.m.

same day, 5 hours, at 300 feet per second 5,400,000

From 2 p.m. to 12 p.m., 400 feet per second for

10 hours 14,832,000

From 12 p.m. 4th, to 9 am. .^th, 450 feet per second for

9 hours 14,580,000

From 9 a.m. 5th, to 7 p.m. 7th, 68 hours, at 450 feet

per second 93,960,000

From 7 p.m. 7th, to 7 p.m. 8th, mean discharge 500 feet

per second, 24 hours 21,600,000

From 7 p.m. 8th, to noon 12th, 89 hoars, at 550 feet per

second .. 176,220,000

From noon 12th to noon 13th, 24 hours, at 450 feet per

second 38,880,000

Total 365,472,000

The quantity of water discharged was equal to a depth of
6}f inches over the whole surface of the collecting ground,
averaging nearly H inch per day for the 5 J days during which
the rain lasted.

The rain at Crowden Hall from the evening of the 3rd to
noon on the 9th, subsequently to which no materia! fall of
rain occurred during the period that the reservoirs were
being emptied, was 5^^ inches. To determine the precise
quantity of water due to the fall of rain, something must be
deducted for the yield of the streams, supposing no rain had
fallen. Their average volume, swollen as they were by pre-
vious rain, would have been about 60 cubic feet per second,
which, for 9 days and 3 hours would have amounted to
59,304,000 cubic feet, — equal to about an inch in depth over
the collecting ground, leaving the nett quantity of water due
to the rain 5| inches, — being ^ of an inch more than the
rain shewn by the Crowden Hall rain gauge.

The results just given from calculations upon the discharge

152

FLOODS AT THK MANCHESTER WATERWOEKS

through the pipes, I believe to be very near the truth —
rather under than over ; but the Woodhead Reservoir afforded
means for still more accurate observation. Here nearly
all the water which reached the reservoir was impounded ;
and, as the capacity of each reservoir had been previously
ascertained by careful survey and measurement, for every
foot in depth, there can be no doubt as to the quantity
of water received.

From eleven o'clock on the morning of the 4th till twelve
o'clock at midnight on the 5th, a period of 37 hours, the
quantity of water impounded in the reservoir was 75,720,000
cubic feet, and the quantity discharged 12,168,000, — making
the total quantity received 87,888,000 cubic feet = 3| inches
of rain over the drainage ground of the reservoir.

From eleven o'clock on the morning of the 4th to the same
hour on the morning of the 5th, the quantity impounded was
02,000,000 cubic feet, and the quantity discharged 3,528,000,
making the total quantity received in 24 hours, from 7,500
acres of ground, 65,528,000 cubic feet, being equal to 2y^
inches of rain. The rain at Crowden during this period
appears to have been S^V To allow for the water which
still remained to flow off the ground before the streams
would regain their usual volume, we must add -^g of an inch,
(after allowing for the natural flow,) making the total quantity
of rain which fell in 24 hours, as measured by the Woodhead
Reservoir, 2-^-^ inches.

The rain which was discharged at Rhodes Wood, or im-
pounded in that reservoir and Torside in the same time,
exclusive of what was received from Woodhead, amounted
to about 66,000,000 cubic feet of water from 7,900 acres,
being, as nearly as may be, the same quantity per acre as that
received at Woodhead. The calculations may, therefore,
be taken to show accurately the quantity of water which
flowed down the river during this extraordinary rain ; show-
ing also, that the average rain over the district, taking the

IN THE MONTH OF FEBBUABY, 1852. 153

whole period, must have been 9 or 10 per cent, greater than
the quantity received by the Crowden Hall rain gauge.

The rain in the district from the commencement of the
year to the 9th of February, as indicated by the several rain
gauges, is as follows : —

January. Febraary, to 9th.

At Crowden Hall 5 inches. 6^ inches.

*• Butteriey Moss 5tV " 6iV "

= Hi inches.

« Black Clough 10t*o "

" Brushes 8^„ to 8th Feb.

« Windyate Edge BA to 8th Feb.

The following table will exhibit the daily quantities during
the first nine days of February : —

Inches.

Sunday, 1st 0.6

Monday, 2nd 0.4

Tuesday, 3rd 0.5

Wednesday, 4th 1.1

Thursday, 5th 1.2

Friday, 6th 0.8

Saturday, 7th 0.2

Sunday, 8th* 1.3

Monday, 9th t 0.5

6.5

On the night of Thursday, the 5th, between 4 p.m. and 8
a.m. of the 6th, there fell 0.7 of an inch of rain.

The quantity of water which flowed from the whole col-
lecting ground of the waterworks, about 18,900 acres in
extent, between the 1st of January and the 9th of February,
exceeded 800,000,000 cubic feet; being nearly 200,000,000
cubic feet more than sufficient to fill all the waterworks
reservoirs had they been empty on new year's day, although

* This was between 4 p.m. on Saturday and 4 p.m. on Sunday.
f This WM from 4 p.m. on Sunday to 12 at noon on Monday.

154

FLOODS AT THE MANCHESTER WATEB WOnKS, ETC.

their capacity is equal to 32,400 cubic feet for every acre of
collecting ground.

No damage of any consequence was sustained by any
portion of the works from the effect of the floods. Their
efficiency was well tested and satisfactorily proved ; but the
heavy rain penetrating into some ancient land slips on the
north side of the valley near the Rhodes Wood embankment,
but above its level, set a mass of about 40 acres in extent in
motion, which disturbed a quantity of masonry and otherwise
deranged the scheme at the spot at which it occurred. The
security of the reservoir is not affected; but it will be a
work of time and skill to arrest or obviate the effects of this
sliding mass.

165

VIII. — On the Identity of Light, Heat, Electricity, Mag-
netism, and Gravitation.

By J. Goodman, M.D., M.R.C.S.

iRead March %ih, 1852.]

In my experimental researches into the identity of these
forces, I have long sought a great desideratum in Science,
viz., an instrument which would give intimation of the pro-
gress and transition of caloric along the molecules of matter,
or the interior construction of bodies, and I believe that
object has been attained in the following experiments.

From the difference of temperature of bodies, — the facility
with which we can increase the temperature of a cold body
by the apposition of one already heated, and of cooling the
latter also by the same contact, — and frona .a knowledge of
the laws of transmission, diffusion, radiation, ignition, coction,
fusion, and volatilization, by this force ; — I cannot, in spite of
all modern theories upon the subject, and the teaching of the
Schools, draw any other conclusion than that this force is a
bond fide imponderable existence, possessing the ordinary
qualities of matter — locality, extension, impenetrability,
resistance, attraction, motion; and, as I believe is shewn
in the following experiments, momentum also — a property
hitherto applied alone to ponderable matter.

That heat possesses the three former properties is not ob-
jected to by philosophers, inasmuch as it is not contended
that it enters into the substance of the atoms or elementary
particles of matter, and occupies with matter the same space

156

ON THE IDENTITY OF LIGHT, HEAT,

at the same time, but simply is described as filling the inter-
stices between these elementary particles. It is also as capa-
ble of transmission from one substance to another, as water
when poured from vessel to vessel. It is to a certain extent
capable of accumulation and retention, without renewal, like
other fluids in nature ; we find that the retention of these
latter is of very short duration if left to evaporate, uncovered
and unprotected, or in contact with leaky or porous sub-
stances.

There is therefore reasonable ground for concluding, that,
as every known substance in nature is ntere or less porous to
the calorific fluid, if caloric could be as effectually sur-
rounded by substances incapable of its transmission as the
liquids in daily use can be, we should be able to preserve it
at any degree of intensity, and that without addition, for any
protracted period.

But it is manifest that whatever may be the teaching of the
Schools with regard to the nature of caloric — they all practi-
cally denominate it not as a mere mode of action or the result
of motion among the particles of matter — but as a bond fide
and genuine substance, and as endowed with all the powers
and qualities usually attributed to real material existences.

The facts that appear to me especially unanswerable, bearing
against modern theory are, that if one were to admit for the
sake of argument that caloric is generated by friction, why does
not the effect cease when the cause is discontinued? — why does
it not cease to exist when friction ceases f — or else, why is not
caloric daily and hourly accumulating ? How is it that when
by such heat generated we have kindled a fire, which might
also be admitted to depend for its development on motion of
a chemical nature occurring among its own particles, — how is
it that by this same fire, once produced, we can communicate
a certain degree of redness or white heat to a piece of iron or
other substance, without producing any motion among its
particles, and with this heated metal we can communicate

ELECTRICITY, MAGNETISM, AND OBAVITATION.

157

warmth to the air, ignite a second fire, or boil water, which
shall absorb just the exact amount of heat lost by the heated
iron, and shall ultimately be able to retain this communi-
cated caloric for a considerable period ?

I think that heat is shewn, by these and other facts, to
have an independent existence, so far as our present ideas of
entity and non-entity extend.

Agib, if caloric were admitted to be the mere creation of
matter, how is it that the other imponderable forces, which
are by many philosophers admitted as convertible into caloric,
and vice versa, are not by them also assigned to the same
origin and the same mode of existence ?

It has already been shewn by the labours of Dr. Wollaston,
Dr. Faraday, and the author of this paper, that the ordi-
nary electric and voltaic forces are identical ; and many years
ago the analogy of aerial electricity, or lightning, was suffi-
ciently demonstrated by the experiments of Dr. Franklin.

The reciprocal influence and mutual dependence of these
forces along with magnetism, and the obedience of electricity
to some of the laws of magnetism, and vice versa, as well as
the analogy of the phenomena manifested by all these forces,
evince their identity. In illustration of the identity of
electricity with magnetism, T read a paper before the British
Association in 1842, in which it was shewn that a plate of
glass maintained in a constant polar condition by the simple
current from the ordinary electrical machine, sustained the
weight of 5 oz. and 20 grs.; shewing that frictional elec-
tricity itself, when placed in a condition resembling mag-
netism— or rather electro-magnetism — will produce with them
an equivalent effect proportionate to its inferior quantity and
powers.

With regard to the identity of light and heat— forces
which 1 hold to be so far identical as to be in their common
acceptation simply the essential qualifies of the one subtile

158

ON THE IDENTITY OF LIGHT, HEAT,

force under investigation — 1 refer to the experimental labours
of M. Melloni and Professor Draper.

We have, therefore, deficient only one link in the chain
of identity among all these imponderable forces, and that
link is the identity of the force light or heat, with electricity.
I have already shewn that there are many points of analogy
between voltaic electricity and the calorific force. Each of
these forces is found occupying the interior or so-called
interstitial space of the elements of bodies, they are the
admitted agents which operate upon the elementary particles
or atoms of matter,* and are possessed of essential qualities
common to both, which are exhibited in all their lumini-
ferous and calorific phenomena.

It is this link which I believe is discovered and supplied
by the following experiments. The account of these is
copied almost verbatim from my experimental note book,
from November, 1850.

My delicate galvanometer, which has been employed in all
my previous experiments, is composed of a helix of forty-six
turns of covered copper wire ^ of an inch in diameter, and
a single needle suspended by about 16 or 18 inches of silk
fibre — the indicator is a slender wooden fibre, and moves over
a card dial, which shades the upper surface of the helix.

I found on placing it in a window having a southern aspect,
that it was impossible in the day time to obtain at all times
certain indications. At other times I observed a constant
vibratory motion to such an extent that I was unable to pro-
ceed with my experiments. Desiring to discover the reason
of such action, on the 14th of November last, the needle
at that time vibrating to a considerable extent, I intercepted
the progress of the suns rays, which were shining upon
the southern extremity of the galvanometer, by a book or any
thing near at hand, and the needle became stationary. On

* This is not the case with any of the other forces. See Keport of British
Association for 1842.

ELECTBICITY, MAGNETISM, AND GRAVITATION. 159

removing the book, deflection again commenced, and the
needle continued to perform vibrations of about 10° so long
as the sun's rays continued upon it.

At 12, (noon,) placed the book again so as to inter-
cept the solar rays, the needle still vibrating; this gra-
dually diminished until it became perfectly stationary, and
remained so up to 12h. 7im, Removed the book, and in
half a minute the galvanometer vibrated to 5°, and became
stationary at 2,^°. Replaced the book, and the needle
returned to 1^°. The sun had now so changed his position
that the other or north extremity of the helix had also
become illuminated. On placing a small book to shade the
latter from the sun's rays, the galvanometer needle slowly
travelled as far as 0^°, then receded to 5"^ below zero, and
kept up a continuous vibration from this point towards zero, —
the instrument having been previously adjusted. On inter-
cepting the sun's rays the galvanometer declined to zero, and
there remained perfectly stationary for five minutes.

At 12h. 20m., the galvanometer being still stationary, I re-
moved the book, and in one minute it had progressed to 2^°.
All action now ceased, and the needle became stationary at
this point.

December 6th, 1850. — Observed the galvanometer at 2^°
at 12, (noon.) Adjusted it; but observed that whenever
the sun began to shine brightly, it became several degrees
deflected. At Ih. 20m., on paying more particular attention
to this circumstance, T found that by interposing a piece of
paper or other screen between the instrument and the solar
rays, the deviation was corrected.

I found that by rectifying the instrument in the sun's rays
and then interposing a screen, the needle deviated to the
left hand 2i°, — and on removing the screen, it speedily
returned to its original station. This experiment I repeated
about every half minute for a dozen times, and the same
results invariably ensued. The needle always answered

160

ON THE IDENTITY OF LIGHT, HEAT,

to the sun's rays when unobstructed, and at all times to the
same distance. (See later experiments.)

3h. p.m. — The needle has now deflected 4^° to 5° in the
sun's rays. On interposing the screen, it returns 2°, and on
removing it, vibrates again to 5^ ; and this action is main-
tained as long as I please, by the mere interposition or
removal of the screen.

Is THIS Thermo-Electric Action ?

In order to see whether the effect was due to any thermo-
electric influence, I retained the south end of the helix in
the mercury cup, exposed to the solar rays, whilst the screen
was interposed ; but this in nowise altered the results. I
then removed the mercury cups altogether ; but the action
of the needle was just as before. The sun is now beginning
to illuminate the north end of the helix as much as the oppo-
site; the action becomes weaker, and in a short time I*' is
the whole effect produced.

December 12th. — The galvanometer has now been sta-
tionary two nights and one day. No sunshine yesterday,
and no deflection.

On the emerging of the sun from behind a cloud this
morning at 11, the needle deflected gradually to 3'^ towards
the right hand. On interposing a screen to obstruct the
rays, it declined speedily to 2^.

When the screen was removed, the sun shining brightly,
the galvanometer indicated 4°. Interposed the screen, gal-
vanometer, 0°. Removed the obstruction, and in one
minute galvanometer indicated 2l°. The power of the solar
rays is indicated with as great precision as with a thermo-
meter ; a cloud intervening, 2° is indicated.

December 13th. — A cloudy day. llh. 55m., the sun has
just emerged, aAd the galvanometer moves 2i° to the right.
The sun is again obstructed, and the indicator stands at zero.
Ih. 55m., some cloudy films intervening, the galvanometer

ELECTRICITY, MAGNETISM, AND GRAVITATION.

161

indicates 4°. More clouds intervene directly, and it returns
to zero again.

December 15th., at 10 a.m. The sun is now in a direct
line with the helix. The indicator 5° to the right hand.
Placed a screen between the sun and the instrument, and
in a few seconds it has returned to zero.

It may be noticed that in all these experiments the sun's
rays had to penetrate the glass of the window as well as
the glass shade of the instrument.

I now used a large lens to condense the rays upon some
of the wires at the south end of the helix, but found that
this condensation deprived the rays of their influence upon
the galvanometer.

That the results were not due to thermo-electric action is
manifest. In these experiments there was no electric circuit
formed. There was no wire of communication between the
two mercury cups forming the terminations of the helix, and
therefore, upon all commonly admitted principles, there could
be neither ordinary voltaic, or thermo-electric phenomena
manifested, for the latter are never seen unless the electrical
circuit is complete.

I now completed the circuit by a connecting copper wire,
one extremity of which was introduced into each mercury
cup. When the sun became partially unclouded, the gal-
vanometer indicated 3*^. I removed the connexion, and
completed it again and again several times, but without any
sensible change.

It is now 4°. I break the circuit, but no effect ensues ;
still 4°. The sun shining brightly, at lOh. 45m., 5°.
The wire of connexion is removed, and after one minute
the galvanometer still indicates 5'^. Clouds intervene,
and the needle declines. The introduction of the con-
necting wire produces no alteration during the decline of
the needle.

Shortly, although clouds of a fine texture intervene, the

162

ON THE IDENTITY OF LIGHT, HEAT,

galvanometer maiks 5°, with no wire of connexion between
the mercury cups. By completing the circuit, no change ;
in two minutes the indicator marks 4°. Removed the
connecting wire, and the galvanometer remains as before,
at 4°.

I now interposed a screen. In ^ min. the needle receded
to Oj° ; in 1^ m., quite to zero. Removed the screen at
11 .20 a.m., and in 1 m. galvanometer 2^°-, in Ik m., 4|° ;
in If m., 5'^; in 2 m., the sun now unclouded, 6°. Circuit
incomplete.

Removed the mercury cup into which the south wire
was inserted — the only one illuminated by the solar rays.
The sun being quite unclouded, the needle indicated lO*^.
I again interposed the screen, and the needle returned to
2^°. Fearing lest the galvanometer had been altered, as
the indication was so high, I removed zero to where the
needle became stationary at 2^°; and on taking away the
screen, in 1 m. the needle indicated 7^^°, and afterwards 8°^.
At llh. 35m., the needle deflected to 9°. The mercu-
rialized end of the galvanometer wire was now enclosed in
paper, to ensure that there should be no supposed thermo-
electric action by heating copper in communication with
mercury; but the galvanometer remained just as before.

There was no alteration in the results obtained by plunging
a wire, in connection with the north end or terminal of the
galvanometer, into cold water.

The sun's rays are beginning to fall upon and illuminate
the north extremity of the helix, and the needle gradually
declines.

.January 3rd, 1851. — All the following deflections were to
the right hand: —

a.m., llh. 30m. Sun somewhat clouded, galvanometer 2°.
" 11 . 45. " brighter, " 2i°,

" 11. 50. " still brighter, " 6^

p.m., 4 . 55. " bright; the galvanometer now indi-
cates 8°.

ELECTRICITY, MAGNETISM, AND GRAVITATION.

163

Interposed a screen, and the galvanometer declined to
zero.

p.m., 2 , 0 Sun clouded, galvanometer 2i°.

" " « more clouded, " 2°.

" " " still more clouded, " 1°.

8^ 0 in the evening. Galvanometer had returned to 0°, as
usual.

January 6th, — One half the extremity of the helix shaded
by a pillar,

a.m., lOh.Om. Galvanometer deflected to S°.

" 11 . 50. Sun clear, unshaded, galvanometer 7i°.
" " Interposed a screen, and in i min. " 5°.

" " Removed " " " Ti".

Repeated, with like results, several times.
** 12 . 0. Sun unclouded, galvanometer 9^,

p.m., 12 . 1. Galvanometer 10°; 1 min. more 11°.
" 12 . 3. Window and apparatus very clean, 12°,
** 12 . 5, Galvanometer 15°.

" 12 . 7i. Ditto 15°.

The instrument had been cleaned and might not have
been correctly adjusted — and probably the last stated degrees
are overrated. The wires at the south extremity of the
, helix, which were originally green, were now inked, so as
to produce a greater facility for the absorption of the rays.
The galvanometer ultimately settled in the evening at 5°,
which would reduce the stated indication of the galvanometer
from 15° to 10°, as before.

January 18th,* a.m., llh. Om. Sun clouded, galva-
nometer lk°,

A little more obscured, 5° ; sun brighter, but

not free from clouds 7^°,

Now 8° ; sun more obscured, galvanometer de-
clined to 4°.

In i a min. 5°; 1 min., sun yet clouded 6°.

164! ON THE IDENTITY OF LIGHT, SEAT,

The motions of the galvanometer appear much more rapid
since the blackening of the extremity of the helix,
p.m., 12h. 45m. The sun is now out again, the gal-
vanometer deflects to 4°, then 5°,

The rays obstructed by a cloud, it declines to ... P.

The sun becoming brighter, 6°; now 7°.

Obscured still by thin clouds, and no prospect of

being clearer 7°.

N.B. Up to this period the deflections had been from the
12th December all to the right hand.

The Vibratory Period.
Effects of Shade — Deflection changed.

January 22nd, 1851, a.m., 9h. 45m. — Half the helix shaded
by a pillar, galvanometer 4° to the right hand. Two-thirds
shaded, galvanometer 2i°. The shade still encroaching, the
galvanometer gradually declines. Now 3 wires only un-
shaded, galvanometer 2°, and at length zero.

llh. 45m. The sun is now brightly shining upon the whole
extremity of the helix and all along the lower bundle of
wires, and the galvanometer remains at zero.

A piece of sheet copper was now interposed as a screen to ,
shade the lower bundle of wires of the helix, and permit
the rays to illuminate only its extremity — galvanometer
deflected to 7i°.

It will be observed that it was the 22nd of January, at
mid-day, and the sun had ascended a consi'derable altitude
above the horizon. The influence hitherto exerted on the
galvanometer appeared destroyed. Sometimes it would diverge
in one direction, and sometimes in the opposite. Vibratory
movements began again to make their appearance as they
had done on the 14th of November, 1850; at which period,
and for some time afterwards, the deflections of the needle
were towards the left hand. By and bye, the galvanometer

BLECTBICITT, MAGNETISM, AND GRAVITATION. 165

settles ; hut its dejlection is reversed, and takes place to the

left, sr.

On interposing a screen, it returns to zero, — and on
removing the obstruction, it is deflected again to the left
hand, 2|°. By alternately intercepting the rays, and then
removing the screen, a continuous vibration is maintained in
the new direction of 21° to 3°.

January 23rd, llh. 30m. — Sun out, galvanometer

deflects to the right hand 7|°.

llh. 40m. Very bright, galvanometer deflects

to the right hand 10°.

llh. 53m. Sun clouded, galvanometer declines 5° .
p.m., 12h. 5m. Sun unclouded, galvanometer de-
flects to the right 9°.

Again —
** 2 0. Sun bright, galvanometer deflects to

the left 2°.

" 2 5. Ditto, ditto ditto 2i°.

" 2 45. Sun obscured, ditto 0°.

January 27th, 9 . 30. — Sun unclouded, galvanometer 5° to
the right hand.

9h. 35m. Sun unclouded, galvanometer 6° to the right
hand.

9h. 55m. The end of the helix is now covered entirely
by the shade of an iron pillar. The left side and surface of
the lower bundle are illuminated by the sun's rays, and the
needle has declined to P.

lOh. Om., a.m. The rays now illuminate one-third of the
end of the helix, and the galvanometer marks 2^° to right.
The left side and lower bundle of the helix was now shaded
by a screen, and the needle speedily marked 6° to the right,
the helix being only half illuminated at its extremity.

lOh. 45m. The sun is now at a considerable altitude above
the horizon, but the glass shade of the instrument is covered

1"6 ON THE IDENTITY OF LIGHT, HEAT,

with condensed vapour internally, and prevents the action of
the rays ; galvanometer at zero.

2h. 15m. The needle is now deflected towards the left 1°.

The whole of the helix (save the extremity) was now
shaded from the rays, and the immediate result was 4' to the
left. The shade was removed, and the needle declined to
21°. Replaced the shade, and the result was 3^° to the left.

2h. 35m. Needle P. Shaded the whole of the helix ex-
cept the south illuminated end, and the result to the left hand
was3^

January 31st. — The greater part of the helix being covered
by the shade of the window frame, the needle began to vibrate,
and continued its vibrations for some time. Shortly after-
wards two-thirds of the extremity of the helix being
illuminated, the needle deflected 4>° to left.

llh. 35m. Sun clouded, galvanometer 3° to left. Helix
shaded, declined to 0°.

2h. 20m. Shaded the helix, 0°. On removing shade, 3=^ to
the left hand.

February 14th, 1851. — Sun much clouded.

9h. 40m. No deflexion ; afterwards shaded the lower half
of the extremity of the helix, result, 1° towards the right.
A cloud intervened, and it declined to 0°.

llh. 20m. GsilyanometeT marks 21° to left. Shaded upper
half, no deflexion ; shaded whole helix, and no deflexion ;
shaded lower half, and galvanometer indicated 5°. This was
repeated several times, with similar results.

Covered the whole length of the silk line supporting the
needle with a paper shade, lest there might be any results
from the action of the rays upon it. The shade was fre-
quently removed and replaced during deflections of the
needle, but no influence appeared to result from these
changes.

12\\. 50m. Galvanometer marks 2i° to the left hand.
The sun becomes bright, and the deflection that ensued was

ELECTBICITY, MAQNETISMj AND GRAVITATION.

167

6° to left. Covering the lower half of the helix now appears
to diminish the amount of deflection.

February 26th, lOh. 55m.— The needle marks 3° to 4° to
the left hand, and by interposing the screen the indicator
returns to zero.

March 3rd, 1 . 40 p.m. — Sun rather clouded ; the galvano-
meter indicates 6° to the left hand. Clouds intervene, and in
a few moments the needle declines to 2i°.

Ih. 45m. The sun again emerged, and the galvanometer
deflected to 6° to the left, and continued to move in one
direction or the other just in proportion to the brightness or
obscured condition of the solar rays.

March 4th, lOh. 54m. — The sun being very bright, the
galvanometer was observed to deviate 10° to the left hand.

In order to see if any similar eflfect could be produced by
ordinary heat, I employed a spirit lamp, held near the
extremity of the helix, but no deflection ensued.

Afterwards I held a pile of red hot burning embers at
the north extremit}'^ of the helix, resting upon a piece of
sheet copper, and a deviation of the needle to the left
hand ensued, equal to about i°. The embers were then
removed to the opposite extremity, when, as the north end
became cooler, the needle passed zero and deflected about
i° to the right. This was performed several times with
similar results. Afterwards the mercury cups were removed,
but the needle deflected under the influence of the embers
just as before.

The shade of the apparatus was heated very considerably
by this proceeding, and much more than by the solar rays for
the production of a deflection of 10°.

June 27th, 1851. — I have since discovered that not only
is the deflection of the needle produced by the solar rays
falling upon the southern extremity of the helix, and ob-
structed by the illumination at the same time of the northern
extremity, but that their projection upon the upper surface

168

ON THE IDENTITY OF LIGHT, HEAT,

of the helix produces an action completely antagonistic to
that of the sun's action upon its southern extremity. Thus
on June 27th, 1850, the opening in the dial card having been
enlarged, the needle deflected to 10° ; exposed the upper
bundles of the helix to the sun's rays, the needle returned
to 7J°, and vibrated continually at this point. Shaded the
dial opening, and the needle deflected to 10°, and after-
wards 11°. This experiment was performed several times
and attended with similar results. By shading the extre-
mity of the helix and exposing its upper surface only, needle
reversed 3° to the right hand.

The powers of reflected light were tried by reflecting the
solar rays upon various portions of the helix, and this in a
variety of directions, but without any change occurring in the
position of the needle.

I also verified the experiments of 1850-51, by similar
experiments in 1851-52, at like periods of the year, but
invariably with the same kind of deflection, and in the
same direction corresponding with the altitude of the sun
above the horizon.

Thus September 10th, 1851, Ih. 30m., deflection to the left
hand, 3°.

At 3h. 45m. The northern extremity of the helix was alone
illuminated, but no deflection of the needle could be obtained.
The same results occurred also in October, and November —
deflection 5° to the left.

The Vibratory Period, 1852.

1852, January 23rd, 12^ p.m. — Deflection to the right hand,
as in the previous year at this date, and the needle returned
to zero on obstructing the rays.

January 30tl), 12 noon. — Galvanometer deflects to the
right hand, the sun becomes obscured, and the needle
returns.

February 12th, lOh. 40m.— Needle deflects 3° to the left

ELECTRICITY, MAGNETISM, AND QUA VI TAT JON.

169

hand; shaded by a pillar, goes back to zero.. At 11 a.m.,
needle stationary, yet the sun very powerful. At lib. iOm.,
the needle deflects 2^ to the right hand; at 3h. iJ^m., it now
vibrates again towards the left hand; shaded the helix, zero;
removed the shade, deflection V to the right hand ; it now
vibrates 2^ to the lefty and continues vibrating.

II h. 20m. Begins by deflection to the right, and then in a
few seconds to the left, then vibrates or remains stationar}'.

12h. 5ra. The needle is now 4i° to the right; shaded, it
returns ; 12h. 10m., deflection 7^° to the right hand.

It is thus seen that the instrument, which is ordinarily
employed for the indication of a voltaic current, and has been
shown also to manifest the transition of ordinary electricity
and lightning, is likewise truly affected by tlie solar beams.

That the effects upon the galvanometer are induced by solar
agency, is clearly manifested in the greater part of the above
experiments by the remarkable coincidence which is ob-
servable between the degrees indicated by the galvanometer
and the brilliancy of the solar beams, as well as by the
changes observed by the interposition or removal of an artifi-
cial screen. (See Experiments, Jan. 3rd, 6th, and 7th.)

That the effects are not the results of thermo-electric action,
is evident, inasmuch as, —

1. There has never been discovered any thermo-electric
phenomenon emanating from the action of heat upon any
simple combinations of copper ivire alone,

2. That there was no thermo-electric influence observable
from the action of heat upon copper in contact tvith the
mercury in the mercury cup, nor upon the mercurialised ex-
tremity of the wire, was seen on the 6th December last ; for
after the removal of the mercury cup and shading the wire
from the sun's rays, the same results were still equally
observable. (See Experiment, Dec. 6.)

3. The;-^ is no hitherto known electric, thermo-electric, or
voltaic action of this kind noticed in science without the

170

ON THE IDENTITY OF LIGHT, HEAT,

formalion of a complete circuit; and yet there was no circuit
formed in most of these experiments, nor did the completion
of the circuit at all augment, decrease, or influence any of the
results. (See Experiments, Dec. 15.)

That the effects are due to the influence of the solar rays
upon the southern extremity of the helix, was manifested on
several occasions by the same and frequently an increased
action upon the needle ensuing by the shading of the other
parts of the helix. (See Experiments, Jan. ^2nd and 27th.)

The unexpected change which took place in the direction
of the needle on the 22nd of January, at 12 noon, and which
appears to have continued from that period to the present at
all times after a given hour, — being to the right hand with the
early and winter sun, and to the left hand when the latter has
advanced far above the horizon, — evinces that the influence of
the rays in inducing the direction of the current in the helix
at these two pei'iods is ajitagonistic ; this is also displayed by
the stationary or vibrating condition of the needle at the
interval between these two periods. This vibratory motion is
also observed at all times when two antagonistic currents are
induced. (See Experiments, Jan. 12th, 23rd, and 27th.)

The vertical action of the rays upon the helix in the
production of current, and its electro-magnetic effects upon
the needle, appear to depend upon the intensity and
momentum of the solar rays, which probably enter into and
traverse the wires in that direction which most nearly cor-
responds to the direction of the rays ; the deflection of the
needle in each instance corresponding, according to known
laws, to the direction of the current thus induced.

That the action is augmented in proportion to the number
of coils of the helix acted upon, was evidenced in several
experiments, and particularly in those of the 22nd of January.

Thus it appears that each ray as it falls upon a coil of the
helix traverses it with a given degree of momentum, and that
when the current thus produced arrives at the continuous

KLECTRICITY, MAGNETISM, AND GRAVITATION.

171

portion of the coil where it becomes subject to the action of a
second ray, its momentum is increased, and probably the
quantity of moving force doubled ; and this increase of
momentum and force is after the same manner augmented in
each succeeding coil by every fresh incidental ray.

The result of these experiments evince to my mind more
than ever the unity of force^ On every band experimental
evidence appears to justify the conclusion that there is one
universal force in Nature, which is modified by the accidental
and varied conditions to which it is subject, but that Us
essential nature and characteristics are at all times the same,
and evince in every modification constantly the same un-
changeable qualities, which are discoverable by man under
the denomination of sensations, as well as luminous and
calorific properties.

I believe that these experiments indicate, and indeed prove
the identity of caloric and voltaic force, and that now the last
required link for the completion of the entire chain of identity
of these imponderable forces is obtained.

173

IX. — On the economical production of Mechanical Effect
from Chemical Forces.

By J. P. Joule, F.R.S., &c.

[Riad April QUi, 1852.]

Perhaps the most important applications of dynamical
theory are those which refer to the production of motive
power from chemical and other actions. To point out the
rules for constructing an engine which shall approach per-
fection as nearly as possible, and to determine the quantity
of work which ought to be evolved by a perfect engine of
any given class, are objects of the greatest consequence in
the present state of society, and which have in fact been to a
great extent already accomplished by the labours of those who
have taken a correct view of the nature of heat. I intend on
the present occasion to submit to the Society some of the
laws which have been recently arrived at by Professor Thomson
and myself, and to offer some hints as to the means of carrying
out into practice the deductions of theory.

Engines which derive their power from the operation of
chemical forces may be divided into three classes. The first
class comprises those exquisite machines in which chemical
forces operate by the mysterious intervention of life, whether
in the animal or vegetable creation. The second class includes
machines in which the chemical forces act through the inter-
vention of electrical currents, as in the ordinary revolving
electro-magnetic apparatus. The third comprises those
engines in which the chemical forces act through the inter-
vention of the heat they produce ; these, which may be

174 ON THE ECONOMICAL PRODUCTION OF

termed thermo-dynamic engines, include steam engines, air
engines, &c.

The process whereby muscular effort is developed in the
living machine is, as might be expected, involved in great
obscurity. Professor Magnus has endeavoured to prove that
the oxygen inspired by an animal does not immediately enter
into combination with the blood, but is mechanically conveyed
by it to the capillary vessels within the muscles^ where it
combines with certain substances, converting them into
carbonic acid and water. The carbonic acid, instead of
oxygen, is then absorbed by the blood, and is discharged
therefrom when it reaches the lungs. Taking this view, we
may admit with Liebig, that at each effort of an animal a por-
tion of muscular fibre unites with oxygen, and that the whole
force of combination is converted by some mysterious process
into muscular power, without any waste in the form of heat.
This conclusion, which is confirmed by the experiments
related in a joint memoir by Dr. Scoresby and myself,
shows that the animal frame, though destined to fulfil so
many other ends, is as an engine more perfect in the economy
of vis viva than any human contrivance.

The electro-magnetic engine presents some features of
similarity to the living machine, and approaches it in the
large proportion of the chemical action which it is able to
evolve as mechanical force. If we denote the intensity of
current electricity when the engine is at rest by a, and the
intensity of current when the engine is at work by b, the
proportion of chemical force converted into motive force

will be - — , and the quantity wasted in the form of heat

will be — . Now from my own experiments, I find that
a

each grain of zinc consumed in a Daniell's battery will raise

the temperature of a lb. of water 0°-1886; and that the heat

which can increase the temperature of a pound of water by

MECHANICAL EFFECT FUOM CHEMICAL FORCES.

175

one degree, is equal to the mechanical force which is able to
raise a weight of 772 lbs. to the height of one foot, or
according to the expression generally used, to 772 foot-
pounds. Therefore the work developed by a grain of zinc
consumed in a Daniell's battery is given by the equation,

a
We now come to the third class of engines, or those in
which the chemical forces act through the intervention of
heat. In the most important of these the immediate agent is
the elasticity of vapour or permanently elastic fluids. In
a very valuable paper on the dynamical theory of heat,
Professor Wm. Thomson has demonstrated that if the heat
evolved by compressing an elastic fluid be equivalent to the
force absorbed in the compression, the proportion of heat con-
verted into mechanical effect by any perfect thermo-dynamic
engine will be equal to the range of temperature divided by
the highest temperature from the absolute zero of tem-
perature. Therefore, if in a perfect steam engine a be the
temperature of the boiler from the absolute zero, and b be the
absolute temperature of the condenser, the fraction of the
entire quantity of heat communicated to the boiler which will
be converted into mechanical force, will be represented by

^ , which is analogous to the fraction representing the
a

proportion of chemical force converteu into mechanical effect
in the electro-magnetic engine.* The entreme simplicity of
this very important deduction which Professor Thomson has
drawn from the dynamical theory of heat, is of itself a strong
argument in favor of that theory, even if it were not already
established by decisive experiments.

• Referring to this analogy, Professor Thompson writes as follows : — " I am
inclined to tbink that an electric current circulating in a closed conductor w heat,
and becomes capable of producing tliermometric effects by being frittered down
into smaller local circuits or 'molecular vortices.'"— Letter to the Author, dated
March 31st, 1852.

176

ON THE ECONOMICAL PRODUCTION OF

Now, estimating the heat generated by the combustion of a
grain of coal at l°-634 per lb. of water, its absolute mechanical
value will amount to 1261-45 foot-pounds; hence, according
to Professor Thomson's formula, the work performed by any
perfect thermo-dynamic engine will, for each grain of coal
consumed, be represented by the equation,

a
which applies, as before intimated, not only to air engines,
but also to those steam engines in which the principle of ex-
pansion is carried to the utmost extent, providing always that
no waste of power is allowed to take place in friction, and
that the entire heat of combustion of the coal is conveyed to
the boiler or air receiver.

Professor Thomson was the first to point out the great
advantages to be anticipated from the air-engine, in con-
sequence of the extensive range of temperature which it may
be made to possess ; and in a paper communicated to the
Royal Society soon afterwards, I described a very simple
engine which fulfils the criterion of perfection according to
Professor Thomson's formula. This engine consists of three
parts, viz., a condensing air pump, a receiver, and an ex-
pansion cylinder; the pump forces atmospheric air into the
receiver, in the receiver its elasticity is increased by the
application of heat, and then the air enters the expansion
cylinder, of which the volume is to that of the pump as the
absolute temperature of the air in the receiver is to that of the
air entering it. The cylinder is furnished with expansion
gear to shut oflf the air, when the same quantity has been
expelled from the receiver as was forced into it by one stroke
of the pump. By this disposition the air is expelled from the
expansion cylinder at the atmospheric pressure, and at the
absolute temperature corresponding with b in Professor
Thomson's formula.

As an example of tho above kind of air-engine, I will take

MECHANICAL EFFECT FBOM CHEMICAL FORCES.

177

one working in atmospheric air of 15 lbs. pressure on the
square inch and 50" Fahr. I will suppose that the expansive
action in the cylinder is to exist through three-fourths of its
length. Then as the action of the compressing pump is the
reverse of that of the cylinder, the piston of the former must
traverse three-fourths of its length before the air is sufficiently
compressed to enter the receiver by its own pressure. The
temperature of the air entering the receiver, determined by

Poisson's equation Jl = (^\ *"\ will be 439'''59 Fahr.,

and its pressure will be 105-92 lbs. on the square inch.
Supposing now that the volume of the cylinder is to that
of the pump as 4 to 3, the density of the air in the receiver
to that forced into it by the pump must be as 3 to 4 in order
to keep the quantity of air in the receiver constant. The
temperature of the air in the receiver will also require to be
kept at 739°* 12 Fahr. in order to maintain the pressure of
105-92 lbs. on the square inch. The air entering the cylinder
at the above pressure and temperature will escape from it at
the end of the stroke at the atmospheric pressure, and at the
temperature 219|°.

It will be remarked that there are two ranges of tempera-
tures in the engine I have described, viz., that of the pump
and that of the cylinder. Owing, however, to the exact pro-
portion which subsists between the two, the same result is
arrived at by the application of Professor Thomson's formula
to either of them. Taking, therefore, the range of the cylin-
der, and converting the temperatures of the air entering and
discharged from the cylinder into the absolute temperatures
from the real zero by adding to them 459°, we obtain for
the work evolved by the consumption of a grain of coal,

^ ^ 1261-45 (1 19812-67866) _ g^.g^ fo„,.pou„dB.

1198-12
In order to compare the foregoing result with the duty of
a steam-engine approaching perfection as nearly as possible, I

2a

178

ON THE ECONOMICAL PRODUCTION OF

will admit that steam may be safely worked at a pressure of
14 atmospheres. The temperature of the boiler correspond-
ing to that pressure will, according to the experiments of the
French Academicians, be 387° Fahr. The temperature of
the condenser might be kept at 80°. Reducing the above
to temperatures reckoned from the absolute zero, we obtain
for the work evolved by the combustion of each grain of coal,
W= '^61-45 (84^-539) ^ ^^^..g fo„t.p„„„a.

It would therefore appear, even in the extreme case which
I have adduced, that the performance of the steam-engine is
considerably inferior to that of the air engine. The supe-
riority of the latter vpould have been still more evident had I
also taken an extreme case as an illustration of its economy.
It must, moreover, be remarked that the heated air escaping
from the engine at a temperature so high as 2191° might be
made available in a variety of ways to increase still more the
quantity of work evolved. A part of this heated air might
also be employed in the furnaces instead of cold atmos-
pheric air.

We may also hope eventually to realize the great advan-
tage which would be secured to the air engine by causing the
air, in its passage from the pump to the cylinder, to come
into contact with the fuel by the combustion of which its
elasticity is to be increased. It appears to me that the air
might pass through a number of air-tight chambers, each
containing ignited fuel, and that whenever any one of the
chambers required replenishing, its connexion with the en-
gine might be cut oif by means of proper valves, until by
removing an air-tight lid or door the chamber could be filled
again with fuel. By means of suitable valves, it would be
easy to regulate the quantity of air passing through each
chamber so as to keep its temperature uniform; and by a
separate pipe, furnished also with valves, by which the air

MECHANICAL EFFECT PROM CHEMICAL FORCES.

179

could be carried from the pump to the upper part of the
chambers without traversing the fuel, the engine man would
be enabled to keep the temperatures of the chambers, as well
as the velocity of the engine, under proper control.

181

X. — On some Trails and Holes found in rocks of the Car-
boniferous Strata, with remarks on the Microconchus
carbonarius.

By E. W. BiNNEY.

iRead April 6tA, 1862.]

Notwithstanding the great attention that has of late years
been bestowed by geologists in investigating the state and
condition of our globe at the time of the formation of the
carboniferous strata, much yet remains to be done. Every
fact connected with the subject, however trivial it may at
first sight appear, deserves to be recorded. The collectors of
fossil shells and plants were for a long time considered by the
practical collier as mere curiosity hunters, whose labours
would do little to guide him in determining the regular suc-
cession of strata or the origin of the coal itself. But the time
has arrived when fossil organic remains have their use in the
mind of the intelligent miner as well as of the distinguished
palaeontologist, by affording valuable assistance in identifying
beds at different places when the deposits themselves are so
changed in appearance as not to be recognized. Doubtless
they require to be used in conjunction with other facts, such
as the mechanical condition of rocks, and various circum-
stances; but still, their value is now so generally allowed
that it will not require any further argument from me for its
support.

In this communication it is my object to direct attention to
the markings which appear upon the surfaces of certain rocks
belonging to the carboniferous strata. The subject has not
particularly engaged the minds of English geologists ; indeed,

182

ON SOME TRAILS AND HOLES FOUND IN ROCKS

SO far as I am aware, little has yet been done in it with the
exception of the investigation of the origin of ripple marks
upon flagstones. This has excited considerable interest, and
it is now pretty well determined that these appearances,
although more frequently indicating the former existence of
sea beaches and beds formed in shallow water, are by no
means to be confined to those conditions, as they have been
found in the present seas under several hundred feet of water.
Your attention will chiefly be requested to the trails of the
former inhabitants of shells and worms, as well as the bur«
rowings of the latter, made on and in the rocks, when they
were in the state of soft sand or mud ; but some observations
will also be made upon those common annelids which have
long passed for molluscs, and were known by the name of
microconckus carbonarius.

The above-named humble memorials of the fauna of the
carboniferous epoch must at present suffice for our con-
sideration. There is little doubt, however, but that rep-
tilian remains will be found amongst the coal measures in
England, like those of Germany and the United States of
America. The tracks and trails as yet met with in these
rocks give no indication of having been made by reptiles, like
those found in the new red sandstone of Weston, Cheshire,
and other places, as well as the old red sandstone of Scotland.
In my cabinet is a vertebra from the roof of the Riley Coal
at Captain Fold, near Heywood, which the most celebrated
living comparative anatomists cannot distinguish from the
caudal vertebra of an ichthyosaurus. As, however, no other
bones were met with in that locality, doubts have been raised
as to the authenticity of the specimen ; but as to its having
really been found in the place where it was represented to
have come from, there is quite as much evidence as of
three-fourths of the fossil remains which are labelled in
cabinets.

Most of the trails and marks found upon the rocks of the

OF THE CABDONiriiROUS STBATA.

183

carboniferous strata have evidently been made by at least two
very different kinds of animals. Some of them have been
excavated by annelids, whilst others have been made by inha-
bitants of univalve and bivalve shells. These trails are often
so much alike as to render it difficult to decide as to which of
the above-named animals it is that we must attribute their
origin. In the Silurian System,* Sir Roderick Murchison
has referred certain markings found upon the Cambrian rocks
of Lampeter to nereites, myrianites, and nemerites. These
fossils Professor Hall, from an examination of many speci-
mens of similar fossils found in the United States of America,
is more inclined to refer to gasteropodous molluscs and
crustaceans analogous to idotea.-\ Without undertaking to
determine which of the above learned authors is correct, I
shall describe in this communication markings, some of which
are the trails of the former inhabitants of shells, and others
as equally certain to have been made by worms.

Mr. William Lee, of Sheffield, in a paper on Fossil Foot-
prints of the Carboniferous System, J after describing several
varieties of what he terms the tracks of reptiles, states, — " In
May last, (1841,) I found upon the moors of FuUwood Head,
five or six miles west of Sheffield, some beds of brown sand-
stone, covered with foot prints, and also with what appear to
be the tracks of worms; (No. 4.) the surfaces are otherwise
exceedingly smooth and even. The beds vary from two
inches thick to one-sixteenth of an inch, and both the upper
and lower surfaces are covered so abundantly with scales of
mica, that it may frequently be scraped off with the fingers.

" The foot prints and worm tracks occur on both sides of
the slabs, the indentations being always on the upper surface,
and the reliefs on the lower.

*■ Silurian System, p. 699.

+ Report of the American Association for the Advancement of Science held at
Cambridge in 1849, p. 257.

X Vol. I. of the Proceedings of the Qeological and Polytechnic Society of the
West Riding of Yorkshire, p. 413.

lS4i

ON SOME TBAILS AND HOLES FOUND IN BOOKS

" Upon one slab, I have without much difficulty deciphered
nearly forty continuous impressions of the same track. The
stride appears to be somewhat more than an inch, and behind
the marks are frequently short furrows similar to those already
described, where the feet have been di'awn along the surface.
No marl or clat/ is found in connexion with the stratum, the
preserving agent in this instance being the interposed mica-
ceous scales."

I have examined the quarry at Fullwood, above alluded to
by Mr. Lee, and found specimens similar to those hereinafter
described as occurring at Scout Mill in the lower flags. The
Scout Mill and Fullwood Head quarries occupy the same
geological position, and I have therefore little doubt but that
the impressions on the surfaces of both flags have been made
by the same kind of animal.

Having made these introductory remarks, it may be as well
to give a section shewing the geological position of the several
strata wherein the fossils occur. This section will be confined
to the limestone shale and the lower division of the Lancashire
coal field. A part of it has appeared in a paper by me, printed
in the first volume of the Transactions of the Manchester
Geological Society.*

SECTION OF THE LOWER DIVISION OP THE LANCASHIRE
COAL FIELD.

This coal is the last thick
seam, and identical with the
Lower Woodley Mine of
Dukinfield, the Riley Mine
of Oldham, the Ariey Mine
at Wigan, the Daubhill Mine
near Bolton, and the Yew-
Tree Mine of St. Helens. In
I, Harwood it is very thin.

* In preparing this section, I have been much assisted by Mr. John Hall, of
Nangreaves, and his brother, Mr. William Hall. The thicknesses of the different
strata are only approximate, and were taken chiefly near Bury and in Rossendale.
Many of the thin coal floors, all containing stigmaria, are omitted.

yds. ft. in.
Coalf Lees, or Dogshaw Mine (the

black Shale Coal of Sheffield.) ... 1 2 0

OP THE CARBONIFEROUS STRATA.

185

yds. ft.

Floor, full of small Ironstone Nodules 1 2
Black, heavy Stone, of a crystalline

structure 1 0

Blue Shale 6 1

Light-ooloored Rock.. 21 0

White earthy Shale 60 0

Very black Shale 30 0

Curled Stone, resembling impure

Gannister 0 2

Light Shale 10 0

Grey flaggy Rock (Old Lawrence),
Elland Flag in Yorkshire 6

Black stony Shale 30

Black Iridescent Shale, containing
Shells of the genera avicula
(pectenj , goniaiites, <i:c. 6

Coal (Pyritous) 0

Black dirty Shale 12

Grey lumpy Shale 3

Brownish dirty Rock, full of black

streaks 4

Hard sharp Sandstone, (Tumbling

Cob Rock,) well seen at Ending

Common, near Whitworth 4

Dark grey Shale, which swells much

on exposui-e to the atmosphere ... 40

Coal 0

Grey Metals 3

This rock is of a red colour
at Harwood and Otterscoe
Bridge, near Marple.

1 6 <

0 0

0 0

1 0

1 6

0 0

' It sometimes exceeds twenty
yards in thickness ; but it is
always parted by layers of
shale, three or four feet thick.
It is worked at Kerridge
near Bollington, Holy Fold in
Romilly, Catlow near Colne,
Bagslate near Rochdale, Har-
wood and Doffcocker near
Bolton, Enfield near Aocring-
ton,'Wrightington, Upholland,

. and Huyton.

This coal is near eighteen
inches thick in the neigh-
, bourhood of Baoup.

2b

186

ON SOME TRAILS AND HOLES FOUND IN BOCKS

yds.

White flaggy Rock, marked with red
streaks and edges 4

Dark Sliale, containing Shells of the
genera avicula (pecten), gonia-
tites, die. 5

Coal (Gannister), excellent for smithy
purposes, and often called the
" Rabbit" and " Mountain" mine,
from the circumstances of its
being generally worked by means
of levels on the hill sides 0

ft. in.
1 6

0 0

Hard heavy Stone, full of itigmaria
ficoides, an excellent material for

roads (Gannister) 0

Smooth white Clay, sometimes chang-
ing into Gannister 0

Light-coloured Stone 4

Grey Metals 5

Black Shale 2

Coal (Foot Mine) 0

Soft brown Stone Floor, containing

layers of Ironstone 1

Black Shale 15

Coal (Bassy), never worked in the
neighbourhood of Bury 0

Grey and Brown Shale 6

Close bedded Rock, which divides
into cubes 3

Excellent light-coloured Building
Stone, (Woodhead Hill and
Lomax Wood Rocks) 7

I 8

' The principal mine of Sta-
leybridge, Waterhead, Roch-
dale, Bacup, Burnley, Black-
bum, Habergham Eaves,
Halliwell, Darwen, Chorley,
Upholland, and Newburgh.
It varies in thickness from
five feet eight inches in Dules-
gate, Todmorden, to about
two inches at Affeside and
Harwood, near Bolton.

1 2

2

0

0

0

0

0

0

0

2

0 -

Principal mine of Qaarlton
and Affeside.

1

0

0

0

The chief mine of New Mills.

2

3

Mellor, Compstall, and Lud-
, worth.

0

0

0 0

0 0 -

One of the best building
stones in the coal series.
This is about its average
thickness, but there are in-
stances of its being much
thicker.

OF THE CARBONIFEROUS STRATA.

187

yJs.

Stony grey SLalo 6

Very black Shale, containing the

avicula (pecfen), goniaiites, &c. 14

Coal 0

Shale Floor 1

Coarse-grained Rock 8

Dark Shale, full of the avicula*
(peden), posidoiiia, and gonial
tiles, mixed with ferns, lepido-

dendra, &c 0

Voal (Feather edge) 0

Rough, or Quartz Rock, full of large
rounded Quartz Pebbles (Old
Mother Rock of Wemeth,&o.)... 12

ft.

in.

0

0

0

0

0

9

0

0

0

0

1 6

2 3

0 0 {

Principal mine of Buxton,
Whaley Bridge, Walmersley,
Lomax Wood, Fecit, and Bir-
tle Dean. The lowest mine
worth working in the vicinity
of Bury.

This rock is often taken for
one of the millstone grits.
It is exposed at Charles-
worth, Wemeth Low, Broad-
bottom, Charlesworth, Black-
stone Edge, Birtle Moor,
Baldingstoue, Cribden, An-
glezark Moor, Pillsworth, Hol-
combe, Turton Tower, Hor-
wich Moor, Grimshaw Delph,
Parbold, and Harrock Hill.

Grey stony Shale, often approaching

to Flags 25

Rough flaggy Rock, provincially

termed "Rag" 4

Fine smooth Flags 2

Strong brown Stone, parted with
Shale, containing thin beds of

Flags SO

Fine-grained Rock, of a bluish colour 2
Grey Shale 8

0 0

0

0

0

0

0

0

0

0

0

0

Edgeworth, Sunnyside, Row-
ley Moor, Fo Edge, Summit,
Shawforth, and Fullwood,
Yorksh.

* This and the next named bed of marine shells are very constant, bat the first
three beds are not always met with.

188

ON SOME TEAILS AND HOLES FOtND IK EOCBJS

yda. ft. iu.

Black Shales, avicula (peetm), drc ... 37 0 0

Coal 0 0 6

Black Shale 2 0 0

Coal 0 0 8

Black Shale 8 0 0

Black Shale, with layers of Stone... 6 0 0

Coal 0 1 3

Dark Shale 4 0 0

tJpper MillstoDC Grit 60 0 0

Dark Shale 40 0 0

Coal 0 0 4

Dark Shale IS 0 0

Coal 0 0 8

Dark Shale

Lower Millstcme, with its partings... 70 0 0

Limestone Shale, containing beds of

Gritstone, about 300 0 0

Ghunal Smmnit Tonnef,
Cheesden Bridge, Sunny-
side, below Holcombe Hill,
Brooksbottom, and Withneli.

Hayfield, Roecross, Saddle-
worth, Gauxholme, Cheesden
Bridge, Brooksbottom, Hol-
combe, Ramsbottom, New
Chm-ch in Pendle, and Brins-
call.

Roecross, Tintwistle, and
Gauxholme, at which last
named place the two smaU
seams of coal are seen.

' Kinder Scout, Tintwistle,
Greenfield, Todmorden, Pen-
. die Hill, and Longridge.

Tintwistle, Todmorden, Pen-
die Hai, and Clitheroe.

With these teraarks, I shall now proceed to describe my
specimens. In the quarry at Hutton Roof, about four miles
from the Burton and Holme Station, on the Lancaster and
Carlisle Railway, a well known flag is worked. This stone
is covered with markings which, although not described to my
knowledge in any published work as the tracks of annelids,
I have seen specimens in cabinets which are generally labelled
as such.

The position of this flagstone is in the limestone shale.
It must be of considerable thickness, as it is exposed to the
extent of full sixty feet. The dip is at an angle of 10°
E.S.E. and the rock lies a short distance above the car-

OF THE CABBONlFKROtJS STRATA. 189

boniferous limestone seen in the vicinity. Tlie beds of stone
vary in thickness from the twentieth part of an inch to six
inches and more. Upon their upper surface is a meandering
trail of about two-tenths of an inch in breadth* This is most
frequently found in relief, but sometimes in intaglio. Fig. 1^
plate Ij drawn on the natural scale, will give an idea of the
nature of the majority of these trails, which cross each other
several times and run to a considerable length. The hollow
trails are deepest in their middle, and have their margins
raised by a slightly elevated ridge of sand.

Besides the trail last described there are two others, namely,
a broad one of half an inch wide, and generally straighter,
but not so long in its course as the smaller ones ; and a double
trail, having markings a little less in size than the first de-
scribed, and about one inch apart, generally running in nearly
straight or slightly curved lines. These last somewhat resem-*
ble the track of small crab on the present sand beaches.

Some of the American tracks are so much like those at
Hutton Roof that a description of the one would nearly
suffice for the other.

At p. 256 of the Proceedings of the American Association
for the advancement of Science, Professor Hall, in describing
the tracks found on thin layers of sandstone^ alternating with
skaly beds, in the lower part of the Clinton group in the
central part of New York, which he considers to have been
made when the bed was exposed above water, or beneath
shallow water only, proceeds as follows : — ** The general cha-
racter of the trails here noticed is that of a meandering furrow,
more deeply depressed at the two sides, elevated at the cen-
tre, and margined by a slightly elevated ridge of sand which
appears to have been pushed outward in the progress of the
animal. Others of them are a simple furrow with the deep-
est depression in the centre ; while others are fimbriated or
ciliated along their whole extent; proving that they were
produced by several distinct species of animals. In their

190

ON SOME TRAILS AND HOLES FOUND IK KOOKS

general character some of them are not unlike the trails made
l)y natica or littorina, and others are more like the mean-
dering trails of idotea^ In many the great length of the
meandering line, which crosses and recrosses itself in many
times, seems to indicate that the animal moved rapidly over
the surface; in others the trails are larger, and the animal
probably moved much more slowly, the length being often
limited to a few inches. These trails vary greatly in size —
from a diameter of half a line to half an inch, — and the
smaller ones as a general rule are the longest, and shew more
recrossings than the larger ones."

In the specimens from Hutton Roof no evidence of the
annelid or mollusc is found, and the trails are the only re-
mains left of the creatures which made them. Doubtless at
the time of the deposition of the beds now forming the flags,
both these departments of the animal kingdom existed, if we
may judge from the organic remains in strata found both above
and below those in which the fossils were met with ; and the
inhabitants of the huccinum gihsoni and other shells found
in the limestone shale, could have made a trail of about the
same size as those of the specimens. From the meandering
character of the trail, crossing itself several times like that of
the littorea littoralis, it bears more evidence of having been
made by a mollusc than an annelid. The bottom, too, of
the trail is flatter, and not so concave as that of a worm
generally is. This also appears to have been the opinion
of Professor Hall, with regard to the American specimens
before alluded to.

In my cabinet is a slab of flagstone from a quarry belonging
to Mr. Jonathan Whitaker, at Dyke Nook, between Hebden
Bridge and Keighley. The stone is much used for making
grindstones. Its upper surface is thickly covered with mean-
dering trails in relief, similar to the smaller ones before
described at Hutton Roof, except that they are about four
times the size of those specimens, and do not cross each other

OP THE CARBONIFEROUS STRATA.

191

so much, but have a straighter course. The upper or relief
side of the trail is marked with transverse striae, veith a slight
ridge in the centre ; the concave side is rather flat, and has a
ridge in the middle. The exact position of this flag in the
carboniferous strata, I am unable at present to give.

In the beds of flags found in the lower division of the
Lancashire coal field, are some sinj^ular markings which have
not yet been much investigated. They occur both in the
upper and lower beds, namely, the Old Lawrence and the
Haslingden flags, and are evidently of different origin.

In the upper bed of flagstones, much used in this neigh-
bourhood for in-door floors, and having very smooth faces,
arc often seen numerous indentations, passing through several
laminas of stone. These shew an orifice on their upper and
a projection on their under surface. An example of these
marks is figured in the paper by the author, printed in vol.
viii. (new series) of the Transactions of the Society, at p. 170.
They are very common both on the Lancashire, Cheshire, and
Yorkshire flags of the upper series, but little, if any, atten-
tion has been hitherto directed to inquire into their origin,
and in my former paper no allusion was made as to the animal
which had caused them.

During the formation of the tunnel on the Bury and Liver-
pool railway at Upholland, in the upper flags there I collected
some of the stones, having very distinct markings on their
surfaces, and upon breaking them crossways, obtained evi-
dence as to the probable cause of the holes in these flags at
least, if not of those found in other places. But it is likely
that other specimens from different localities, if carefully
examined, will afford similar evidence. The upper part of
the holes in the larger specimens is about eight-tenths of an
inch in diameter, and gradually tapers to a depth of nine-
tenths, and then, by a curved orifice of two-tenths of an inch,
is connected with another conical hole like the first. These
holes, a good example of which is shewn in fig. ^, plate 1,

192

ON SOME TRAILS AND HOLES FOUND IN EOCKS

drawn on tlie natural scale, appear to shew that they were
formed by an animal of Cuvier's division of annelides of
the second family, or dorsibranchiata, where the external
breathing organs or gills, often resembling beautiful feathery
tufts, are attached in pairs, either to every segment of the
body, or to a certain number of middle segments. The
organs often display the most elegant varieties of form and
the richest colours. To this order belong the majority of
the present marine annelids, and, among the rest, the com-
mon lug worm, arenicola piscatprium. It is to this last
named annelid, or one nearly allied to it, that I am inclined
to attribute the holes above described. The fossil holes are
smaller than the recent ones. With this exception, the
only difference that I can detect betwixt the fossil holes and
those at present found on our sandy shores is, that there
are no traces of the coils of sand at the vent end of the
hole, which so generally accompany those of the lug worm
at the present day. These may have been formed under
water, and afterwards washed away, but certainly I have not
yet been able to detect any near the fossil specimens. The
animal which inhabited the hole appears to have drawn in
the water and sand by one opening, and ejected them from
the other.

For a provisional name I have designated the animal which
made the holes arenicola carbonarius.

Upon the surfaces of some of the finer beds of the lower
flag deposit are often seen numerous depressions of a more
elongated and bent form than those last described as occurring
in the upper flags. Some of them are about an inch in
length and a quarter of an inch in breadth. Near to these
are sometimes seen traces of a furrow or trail, more or less
distinct according to the nature of the flag, whether it is fine
and smooth-faced or otherwise. They are seen in the flags of
Edgeworth near Bolton, Fo Edge near Bury, Shawforth
near Rochdale, and other places where the lower flags are

OF THE CARBONIFEROUS STRATA.

193

extensively worked. For some years T have been of opinion
that these deep impressions were the casts of a bivalve shell,
and the shallow ones its trail in the sand, when the latter
was in a soft state.

During the cutting '^f the Manchester and Huddersfield
Railway through the lower flagstones at Scout Mill, between
Staleybridge and Mossley, I found a specimen which gave me
decisive proof that I was not mistaken in my former opinion.
In this specimen, figured at plate II. fig. 1, drawn on a scale
of one-seventh the natural size, the casts of several shells,
apparently of the genus modiola, with their trails, are dis-
tinctly seen. The curve which the animal made in its track
much resembles that of the psammobia solidula on the soft
mud of our present coasts, and presents a very marked dif-
ference to the meandering trails of the littorina and some
other univalves, to which the most common trails on the
flags of Hutton Roof, if they are not worm marks, must be
referred.

The whole appearance of the trail leads me to believe that
it was Ibrmed under shallow water, just as we now see indivi-
duals of the geneva psammobia and naticof nake trails upon
the mud at the bottom of the pools on the sea shore. And in
confirmation of this view I may add, that the thin beds of
clay separating the deposits of flags shew no evidence of
desiccation by cracks in them, which they would have done if
they had been exposed to the sun's rays.

In a paper by me, printed in vol. viii. of the Society's
Memoirs, at p. 171 is figured the cast of a small annelid of
nearly the shape of the letter S, about an inch long and a
line in breadth. It is merely a cast of the animal itself with-
out any trail, in a bed of fine sandstone, and found by me in
the lower flags near Todmorden.

I shall now proceed to make some observations on a spiral
fossil shell frequently found in the Lancashire coal field, and
long known by the name of microconchus carbonarius, Mr.

2c

194

ON SOME TRAILS AND HOLES FOUND IN ROCKS

Martin, in his Petrificata Derbiensia, figures this shell as
conchyliolithus helicites, (pusillus plate 25,) and states it to
be of rare occurrence in the coal shale near Chesterfield.
The occurrence of it near the last-named town, in the lower
part of the middle division of the coal field, I can fully con-
firm ; but it is far from rare, being there met with in consi-
derable abundance. Sir Roderick Murchison, in his Silurian
System, at p. 84, in speaking of the limestone found in the
higher part of the coal field near Shrewsbury, states, — "That
the characteristic fossil of the limestone is a very minute
discoid univalve, resembling on first inspection jplanorbis nau-
tilus, Fleming, and with it is a small bivalve resembling a
cyclas."

At p. 88 of the Silurian System, Professor John Phillips, in
describing the Ardwick limestone, states, — "Among the shells
the most characteristic is a microscopic spiral shell of few
volutions, which touch one another like the planorhis when
young, but when old are exhausted into a free tube like
vermetus, or rather like vermilia. The shell is sinistral like
jplanorbis, but sometimes shews proof of its being attached on
one side like spirorbis — lines of growth strong, somewhat
irregular, deficient in parallelism, and oblique to the axis of
the tube as in planorhis ; faint spiral striae can just be seen.
This shell, which I have identified with your Salopian
planorboid shell, is also probably the same as a species I have
seen from the coal measures of Fitzgerald's colliery,* near
Manchester, as well as from the lower part of the Yorkshire
and Newcastle coal field."

Dr. Hibbert,f in noticing this fossil, states that it appears
in a crushed and broken state. In this form they exhibit a

* After many years' search I have certainly found the fossil at this place, but
In nothing like the abundance as at the Bradford and Clayton collieries, where it
occurs in great profusion.

+ On the Freshwater Limestone of Burdiehouse, &c. Transactions of the
Boyal Society of Edinburgh, vol. xiii., part 1, p. 180.

OF THE CABBONIFEROUS STBATA.

196

sort of spiral organization, by no means unlike that of the
planorbis or spirorbis, to which they were referred by an
eminent conchologist, whose opinion regarding them I have
consulted. But on renewed examination of these remains,
which, owing to an infiltration of calcareous matter, have had
their forms tolerably well preserved, I am now inclined to place
some doubt upon the judgment which had been passed upon
their character. The external form of one animal most resem-
bles that of the nautilus, but we are totally precluded from
identifying it with that class of mollusca, as the internal con-
stitution of its shell shews no septa whatever, but on the
contrary, approaches to that of the planorbis. It may, per-
haps, be considered as a new genus altogether — referable to
mollusca"

Mr. Morris, F.G.S., in his excellent Catalogue of British
Fossils, also classes it amongst mollusca.

Professor Goldfuss* considers the microconchus an annelid,
like the spirorbis, and describes it as S. omphaloides. Col.
Portlock, in his Memoir of the Geological Survey of Ireland,
describes it under the same name. Sir Charles Lyell, in the
last edition of his Manual of Geology, at p. 324-5, still calls
the fossil microconchus carbonarius ; but describes it as " the
microscopic shell of an annelid of an extinct genus allied to
serpula or spirorbis."

From the above quotations it is pretty evident that consi-
derable doubt has existed as to whether or not the microcon-
chus should be classed with mollusca or annelata.

In the Lancashire coal field this fossil is found from the
lowest up to the highest strata — generally in black bass.
In the roof of Mr. Stock's coal at Shaly Brow near Bil-
linge, it constitutes a bed of about six inches in thickness,
and is mingled with the remains of fishes. In the thick bed
of large shells lying about fifty yards above the Arley Mine»

* Howse, T. N. I. C^ vol. i. p. 259. 1848.

196

ON SOME TRAILS AND HOLES FOUND IN EOCKS

and indeed in all other beds of shells which have been gene-
rally classed under the genus unio, it has been found. Most
of the black shales forming the roofs of the coals in the mid-
dle and upper coal fields, and the limestones of Ardwick,
yield it. But, with the exception of Shaly Brow, it is the
most plentiful in the roofs of the yard and three-quarter
mines of Bradford near Manchester, mingled with a mass of
cypriS) and detached bones, scales, and teeth of fishes.

The genus microconchus probably had better for the
present be divided into two genera, namely, spirorbis and
serpula; under spirorbis, I propose to class, —

1st. The small one figured by Sir R. Murchison, found in
the shales and limestones of Ardwick. This is sometimes
attached to plants and shells found in the shales, and has evi-
dently lived as a parasite both on floating plants and shells,
lying at the bottom of the waters just as the common spirorbis
now found on our shores does. The specimen described in
plate II. fig. 3, is one-twentieth of an inch in diameter, and
was found by me on a fossil bivalve shell from the roof of the
Four Feet Mine at Bradford near Manchester. I propose to
call it spirorbis carbonarius.

2nd. S. omphaloides, of Goldfuss and Portlock. A large
species, found in many places, especially amongst the bed of
large bivalve shells lying above the Arley Mine at Wigan,
and other places, and the shales of Shaly Brow. This species
apppears to be identical with the one found by Martin, near
Chesterfield, and figured by him under the name of conchy-
liolithus heliciles. The specimen described in plate II. fig. 4,
is two-tenths of an inch in diameter, and was found by me in
the roof of the lower seam of coal in Mr. Stock's colliery at
Shaly Brow.

The large uncoiled shell appears to me more properly
arranged under serpula. It is by no means so common as the
two species of spirorbis previously described, and I have not
yet found it attached to fossil plants or shells like those, but

OF THE CAKBONIFEROUS STBATA.

197

free. My specimen figured in plate II. fig. 2, twice the natural
size, is from the limestone of the upper coal measures at
Ardwick. It is very like the shell mentioned by Professor
John Phillips at p. 88 of the Silurian Systeinj, previously
quoted, but larger in size. This author classed it with one,
if not both of the two species of spirorhis before mentioned,
and considered it as merely a specimen of more advanced age.
However, I have not met with any graduation of the spirorhis
into serpula either in recent or fossil specimens. The com-
mencement of the fossil shell in its first volutions is like
that of the spirorhis, but it then extends into a free tube like
vermilia. My specimen is three-tenths of an inch in length,
and one-twentieth of an inch in diameter at the broadest
portion of the shell. It is covered with irregular striae, placed
rather oblique to the axis of the tube, which is cylindrical.
From its characters and the places where it is found, both
differing from those of the spirorhis, I propose to call it the
serpula carhonarius. It resembles serpula more than any-
thing else ; and I have not yet found it attached to fossil
shells or plants like the spirorhis.

The two species of spirorhis described in this paper, from
their external characters and the places where they are found
attached to the surfaces of shells and plants, lead strongly to
the conclusion that they belonged to parasitical annelids like
the common spirorhis, (serpula spirorhis of Penn. Brit. Zool.,
No. 155, tab. 91, fig. 155.) But I am bound to state that I
have seen a specimen of a fern from the liancashire coal field
belonging to Mr. Matthew Dawes, F.G.S., with several shells
not to be distinguished from the small species previously
described embedded in the substance of the fossil. In my
own cabinet there is a specimen of a small sigillaria from the
roof of the Riley Mine at Captain Fold near Heywood.
The substance of this fossil is clay ironstone, but the epider-
mis of the plant is converted into coal. Under the coaly
envelope are numerous specimens of a shell like the spirorhis

198

ON SOME TRAILS AND HOLES FOUNB IN ROCKS

omphaloides, embedded in the body of the fossil two-tenths of
an inch in depth. It is possible in both these instances that
when the fossil plants were in a soft pulpy state, and the shells
were attached to them, superincumbent pressure might have
squeezed the shells into the substance of the plants. But in
both cases we should expect to discover some portion of the
coaly matter squeezed in as well. This I do not find.

Now is it probable that some of the shells described as
belonging to the genus spirorbis were inhabited by boring
molluscs or worms ? In the bed of shells before alluded to
as occurring above the Arley Mine at Wigan, and generally
termed large unios, (?) are many specimens having holes bored
in them, — thus plainly shewing that boring molluscs or worms
did then exist. In this bed the spirorbis abounds as well as
the so-called unio. So after all the disputes as to the nature
of the microconchus, it may possibly be that in some species
at least its inhabitant was a mollusc allied to teredo, and not
an annelid, as has generally been supposed.

In former communications* published by the author he has
brought forward both the fossil fishes and the fossil plants, to
shew that the waters of the carboniferous epoch were nearly
if not altogether of a marine character. The facts described
in this paper of the meandering trails of molluscs, the bur-
rowings of worms, the occurrence of shells pierced with
boring animals, and the parasitical annelids found attached to
plants and shells, all tend to the same conclusion. But
beyond all other proof of the marine character of the water
of the carboniferous age, is the water itself now found mixed
with the coal, and where it has remained for countless ages
pent up and hermetically sealed. In deep mines, where the
seams of coal have not been subjected to the percolation of
surface water, but protected by compact beds of indurated
clay, the water is nearly always saline, and contains iodine

* Transactions of the Manchester Geological Society, vol. i. p. 173 ; Memoirs
of this Society, vol. viii. (new series) pp. 24 —

OF THE CARBONIFEROUS STRATA. 199

and bromine, together with all the salts usually found in the
waters of the present ocean.

The numerous trails throughout successive strata, and the
preservation of the habitations of such frail creatures as
worms, shew that the deposits took considerable time in their
formation and were made in great quietude. In fact every
thing indicates that the deposits which we have been investi-
gating went on from time to time with as great regularity,
and in very nearly the same manner, as beds of sand and mud
are now forming in the ordinary course of nature on and near
our present shores, — although we cannot well distinguish
regular tidal deposits, such as are now taking place.

In bringing this dry, and I fear uninteresting, paper to a
close, I wish to direct the attention of my readers to the trails
of molluscs and the burrowings of worms now to be seen on
our sea shores. And for this purpose I cannot do better than
refer them to a charming little work of Dr. Harvey's, intituled
"The Sea-side Companion," and conclude with an extract
from it. At p. 25 of his book he says, —

" The foot-prints of sea birds on the sands of the shore are
often unnoticed, and are swept away by the first returning
wave. So are the tracks of trailing shell-fish, which may
sometimes be seen furrowing the surface of fine hard sand in
considerable numbers. The common yellow nerite (littorina
littoralis) is a frequent maker of these trails, as it moves its
station from one small rock to another, patiently cutting a
road through the sands as it proceeds on its journey. These
marks, and the undulation left by the water on the surface,
where regular minute ridges of sand follow each other in an
orderly manner, like the furrows in a field, appear of so fuga-
cious a nature as to be undeserving of notice. The retreating
wave has left them behind, and the returning will sweep them
away, and all be a smooth surface again. Yet, in these fugi-
tive markings of the sand the geologist traces a resemblance
which links them with time immeasurably distant in the past

200

ON SOME TBAILS AND HOLES FOUND IN ROCKS

history of the world, and with impressions on rocks which
have outlived the decay of centuries, but which were, in their
origin, of no more apparent stability than these marks in the
sand, or than our own foot-prints. When a surface of sand-
stone rock is uncovered, it very frequently exhibits markings
of a nature precisely similar to what we every day meet
with on the sandy shore. There is the ripple-mark, defined
with equal regularity and sharpness — we see where every
wavelet of the antediluvian ocean did its work ; — there are the
sinuous roads, cut out by the antediluvian molluscs now visi-
ble in relief, by the mud which has silted into them ; — the
worm-like heaps of sand, which mark the position of the
worm, or of the testaceous mollusc, are equally obvious in the
sandstone, and on the recent shore ; — the very rain-drops
which impressed the sandy surface thousands of years ago
have left their record on the surface of the rock. When we
see all these appearances on the newly turned up rock, and
find similar markings on the flat sands of the sea, it is impos-
sible to avoid connecting the two observations, and admitting
that in what passes under our eyes as a daily occurrence on the
sands, we find the explanation of the geological phenomenon.
The sandstone rock, hard as it now may be, was once a beach,
as impressible as that in which we may now be leaving our
foot-prints. And though, in thousands of cases, these foot-
prints will be swept away by the next flow of the water, it
may so happen that they will remain. And it is a wonderful
circumstance that all trace of soriie of the gigantic animals
which once inhabited the world has perished from the know-
ledge of mankind, save only the track of their foot-prints
left in what was then adhesive mud, but which successive ages
have converted into hard stone. If Robinson Crusoe was
powerfully affected by meeting with the naked human foot-
print in the sand, what a crowd of thoughts are awakened by
discovering, in the hard rock, this only evidence of a gigantic
animal. A true poet has said, —

PLATE,!.

Fi^.l

Tit 2

f<i^^m^mii>

•§4Jt*

PLATE

«.i<u»ssi*K**ff*«=ateSk

/l

H

■%,

['''%;f?s'tsr«'

^FilS

3 cliaiaf

Pl4.4.

OF THE CABBONIFEROUS STRATA. 201

' It is the soul that sees : the outward eyes
Present the object, but the mmd descries;
And thence delight, disgust, or cool indiflfrence rise.'

** We may live among the grandest scenes of nature, or may
visit the noblest monuments of art, and remain insensible to
their beauty or sublimity. Differently affected, we may find
in the barren sands of the sea shore enjoyment of the purest
character, and speculations which, rising from nothing more
important than the trail of a sea slug, will lead us to contem-
plate, and in some measure to comprehend, some of the most
extensive operations of nature, and bring under review un-
numbered ages, past, present, and to come."

Explanation of the Plates.

Plate I. fig. 1. Upper surface of a flag of sandstone from
Hutton Roof, shewing the trail of a mollusc, (?) drawn on the
natural size.

Fig. 2. Upper surface and side view of a flag of sandstone
from the Bury and Liverpool Railway near Upholland, shew-
ing the holes of the arenicola carbonarius, drawn on the
natural size.

Plate II. fig. 1. Upper surface of a flag of sandstone from
Scout Mill near Stalybridge, shewing the casts and trail of a
bivalve shell, drawn on a scale of one-seventh the natural
size.

Fig. 2. Serpula carbonarius, from the upper carboniferous
limestone of Ardwick, on a scale of twice the natural size.

Fig. 3. Spirorhis carbonarius, from the roof of the Four
Feet Mine, Bradford, twice the natural size.

Fig. 4. Spirorbis omphaloides, from the roof of Mr. Stocks'
coal at Shaly Brow, twice the natural size.

2d

203

XI. — A Biographical Notice of Peter Clare, Esq., F.R.A.S.
By the Rev. H. H. Jones, F.R.A.S.

[Read April 6<A, 1852.]

The late Peter Clare, Esq., was born in Manchester, in the
early part of the year 1781, but the exact date of his birth
as far as we are aware is not known. While quite a youth
he was accustomed to assist his father, who was in the habit
of giving occasional lectures on electricity, and some kindred
subjects in natural philosophy, illustrated by experiments.

The son, in consequence of his early habits of thought-
fulness and inquiry, was not unfrequently admitted to the
meetings of the Literary and Philosophical Society of Man-
chester, while he was yet ineligible for membership on
account of his minority. And though he had arrived at the
requisite age some years before, his modesty held him back
till 1810, in which year he was regularly proposed and elected
an ordinary member of the Society.

Commending himself, by his constant attendance and uni-
form assiduity, to the approbation of his philosophic friends,
he was in the course of a few years made a member of the
Council, or as it was then designated, "The Committee of
Papers." Subsequently (I believe it was in the year 1821)
he became one of the Secretaries ; and during the last several
years of his life, he held the office of Vice-President of the
Society ; the duties of which office he continued to discharge
with unremitting attention till disabled by bis last fatal
illness.

In the year 1841 he was made a Fellow of the Royal
Astronomical Society. And though he was constitutionally

204

A BIOGRAPHICAL NOTICE

unfitted for the frequent and persevering use of the telescope,
and his residence in Quay-street subjected him to great local
disadvantages, yet in the discoveries and progress of astro-
nomy he continued to take a keen and unabated interest to
the very last.

It is true Mr. Clare was not a profound student, nor was
he a frequent contributor to the publications or memoirs of
any of the literary or scientific institutions with which he
stood connected. But he was an ever active friend to those
who took a more prominent or adventurous part than himself
in the proceedings of such societies, — was thoroughly imbued
with a taste for philosophical investigation, — and was acknow-
ledged by all who knew him intimately, to be a man of very
varied and extensive information.

But that which (in the estimation of many) will form the
most distinguishing circumstance in the life of Mr. Clare, is
the fact that he was for many years the most intimate friend
and almost constant companion of Manchester's greatest cele-
brity— the late Dr. John Dalton. The high estimation in
which he was held by this celebrated man is sufficiently
evinced by the Doctor's leaving him a handsome legacy, and
also appointing him one of his executors.

In the religious and political circles of the day, Mr, Clare
was extensively known as a prominent, zealous, and untiring
member of the anti-slavery committee. In this capacity he
was honoured by being placed on several deputations to the
Government, while measures for the abolition of slavery were
under their consideration.

In person Mr. Clare was a trifle below rather than above
the middle stature.* He was always remarkably well dressed ;
and his bland and portly aspect was calculated to produce an

* Since tte above was written, an excellent portrait of Mr. Clare, by Bradley,
has been bequeathed to the Literary and Philosophical Society by the late
Samuel E. Cbttam, Esi}., for many years an intimate fnend of Mr. Clare, and
whose loss also the Society has now to deplore.

OF PETER CLARE, ESQ., F.R.A.S. 205

impression in his favour, which occasionally arrested the
attention of strangers, and induced them to inquire for his
name. While in health he was uniformly cheerful. In the
social circle he was always entertaining, and not unfrequently
facetious, having a good memory and a large fund of humor-
ous anecdotes and amusing narratives at command. As a
natural consequence, his company was often sought and
always acceptable.

Like his illustrious friend Dr. Dalton, he was brought up a
Quaker. To that denomination he adhered through life.
But he never unseasonably obtruded his religious opinions
upon others. In fact, he always comported himself with the
unaffected ease and urbanity of a real gentleman, continually
exemplifying in the mild and ** even tenor of his way" the
beautiful sentiment of old Geoffrey Chaucer, — "He who ever
intendeth to perform all kinds of gentle deeds, is the greatest
gentleman ; and he who will perform none of them —

He is not gentle, be he duke or earl."

Mr. Clare was never married ; and has left very few near
relations to mourn his loss. His last illness was long, but
not painful. The disease under which he finally sank is
believed to have been an affection of the heart. He died on
Monday, November 24th, 1851, in the seventy-first year of
his age, and was interred on the following Sunday morning in
the "Friends'" burying ground. Mount-street, Manchester.
His remains were followed to their last resting place by a
numerous body of his own denomination — by the President,
Council, and other members of the Literary and Philosophical
Society, and a large concourse of spectators.

Peter Clare was in every sense a truly respectable and
much respected man, — an ornament to the connection in
which he moved, — and sincerely regretted by a wide circle
of acquaintances and friends.

207

XII. — On the Air and Rain of Manchester.
By Robert Angus Smith, Ph. D. F.C.S.

[Read May 4th, 1852.]

Last year I read a, paper on this subject, somewhat different
in title, to the British Association. As a very imperfect
abstract was printed I have again written the paper, giving
no new facts, but using different words.

My object is to shew that there are impurities in our
atmosphere which may be discovered by chemical analysis,
and that the senses and general impressions are not at fault
when they speak of the peculiarities of a town's atmosphere.
I had shewn in a former paper that it was not a mere fancy
to suppose that the air of crowded rooms was tainted, and
that it contained a substance capable of nourishing organic
forms, and therefore in itself organic; and although by no
means a new idea, as may be shewn from old writers, I con-
sider it of importance that these things should not rest merely
on ordinary observation, but should be more and more brought
under the domain of careful experiment.

It had often been said that we were unable to tell the dif-
ference betwixt good air of the finest mountain side, and the
worst air of the hospitals, — or rather, we should now say, of
the infected dens of large towns, so well described in various
forms, of late years, to the public. It seemed to many as if
the eye had obtained a mysterious power of seeing what was
scarcely capable of being proved within the domain of sub-
stance, and the smell had a power of observing what was
more an influence than a positive thing. These modes of

208

ON THE AIR AND BAIN OF MANCHE8TEB.

thinking are too indefinite to be considered as opinions, and
they belong also to that state of mind so common to early
ages, and not uncommon in our own times, which confounds
the idea of substance and elements with the ideas of power
and character. These words may certainly be made to bear a
closely approaching signification when viewed from a meta-
physical point of view, but in physical science their limits are
distinct.

The air has been a fertile source of inquiry and speculation
in all times ; the early writers seem lost in the vastness and
vagueness of the subject, and the history of opinion upon it,
up almost to the present century, is like the history of some
non-physical or metaphysical subject. It is a common notion
that our mental part must resemble air, and we might readily
make an interesting history of the indefinite ideas and con-
fused reasoning which introduced into our language such ex-
pressions as " the spirit of wine" and "pneumatic chemistry."
But here, as in many other cases, whilst the true solution has
been difficult and late, the main points have been seized very
early, and whilst we may fairly object to, or smile at the
use of phrases which shew our opinions to be taken from
those who thought, like Anaximenes, that the soul was
aerial, we scarcely diflfer from him when we say, as we may
fairly do, " that plants and animals are made of air and return
to air."

We cannot say much for the increase of clearness of
thought when we compare this with a description of air
written (per Johnsonum Chymicum) in 1552. " Aer est spi-
ritus, spiritus est ventus," " The air is spirit, spirit is wind."
Nor even coming later, to the time of Stahl, who lived at the
beginning of the last century, and who had followers, great
men, also in this century, do we see it much improved. Stahl
says, — "Air is nothing but aether mixed with aqueous efiluvia
and the exhalations of solid bodies." Also he calls it in better
style, " a light dry body, mixed with various particles of saline,

ON THE AIR ANDRATN OP MANCHESTER. 209

sulphureous, and aqueous salts." Here, however, is brought
prominently forward an opinion of long standing, the mix-
ture of solids with the air, giving rise to the expressions,
"lighter and denser," "moist and earthy," "mixed with the
exhalations of the earth." " Terreni halitu miscens" are
Pliny's words.

Des Cartes found it necessary, therefore, to give a more
minute description of air : " We know that air can be no-
thing but a collection of particles of the third element — that
it is a fluid very rare and pellucid," distinctly bringing it
under the class of ordinary material bodies, and taking it from
the sphere of mind.

The great difference of difi'erent airs, and the effect they
have in the system in raising or depressing the spirits, have no
doubt been causes why air should have had many indefinite
notions connected with it, independent of the ordinary want of
a correct definition of matter, and the peculiar difficulties
in the case of a body which cannot be seen. When a person
is depressed in one place, and elevated in another, he is not
unwilling to believe the very poetical idea of Heraditus that
" we receive our life by breathing in the air the soul of the
world." And to a great extent there is a practical truth in
this, as we are often found to possess more or less life accord-
ing to the condition of the air.

Modern chemistry has gone far towards proving the correct-
ness of ancient impressions, that the air goes with the blood
through the whole body, and some have almost gone as far
as a Greek philosopher, who said that " the soul is in the
lungs."

As so many opinions have already been delivered on air, it
is not easy for any one to bring forward more beautiful or
more expansive ones ; there is room, however, for experi-
ments to make our ideas more definite. We hear of pure
and impure air, but these phrases do not convey the same
meaning to all persons. Impure air is simply air with impu-

2e

210

ON THE Jm. AND .KAIN OF MANCHESTER.

rity in it ; to some it means a different kind of air inherently
impure. This vague and alchemistic notion, which did not
distinctly define, was combatted in speaking of compounds
generally, even by Roger Bacon, but it was not until Dalton's
time that any distinct notions of compound bodies became
general, notwithstanding Newton's definition of atoms.

The number of analyses of air in order to ascertain its
oxygen and nitrogen, have been very great, and many also
exist which determine the carbonic acid ; little, however, has
been done in ascertaining the other possible contents, and
some eminent names have rather discouraged the idea of find-
ing any thing, because if any thing else did exist, the amount
would be too small for analysis to detect, and therefore too
small for the body to be affected by it. Some such mode of
reasoning has been current, but it is not in our power to tell
what is the smallest amount of matter which will affect the
system, and we know that exceedingly small doses affect us
if taken repeatedly, although that effect is not equal to the
effect of taking the whole at once.

Whatever chemistry or scientific men have said about the
air, or indeed about any thing else, common sense and ordi-
nary observation have had their force in no way diminished,
and it is wiser for science to explain the large generalizations
of common sense and the teachings of instinct, than to run
counter to them ; by which means it produces on one side at
times extraordinary scepticism, and on the other extraordinary
credulity.

Our senses are often much superior as tests to chemical tests,
that is, we can perceive by our senses very often less than we
can test; but it is not always the case, and when the amount
is too small for either mode of observation, experiment has
the great advantage of being able to condense and to accumu-
late, and so bring everything within the region of the sight.
But it is not to be supposed that because we bring within the
limits of a glass vessel enough of the impurities of the atmo-

ON THE AIR AND RAIN OF MANCHESTER.

211

sphere to allow us to see them, there is therefore any
greater proof that the air had these impurities in them. It
was well known before. The action on the system for so
many years, producing almost a different race of men, is a
stronger proof of a chemical action than any thing done in a
bottle. This difference of feeling which we have in different
atmospheres, may be said to be perceived by our chemical
senses, as the effect is produced by decomposition in the
S3''stem, and not by physical contact, otherwise we should feel
the pain on the skin, or at furthest in the lungs. After
breathing certain gases, either sulphuretted hydrogen, sul-
phuric acid, nitrous gases, muriatic acid, or chlorine, a certain
lassitude and an inclination towards anxiety is felt; certain
decompositions have been put in motion, and certain others
have been arrested, which produce this result in the system,
and we have been very slightly inconvenienced by their action
on our ordinary senses. But it may happen also that our
ordinary senses have perceived nothing at all, whilst illness*
elevation, or depression of some kind, which are modes by
which we feel a chemical action, prove it to have taken place.

The air of our towns generally seems to waver between
these two states ; in some cases it is shewn to be hurtful by
our ordinary senses, in others it can only be felt in a secondary
manner, or by what it is fairer to call our chemical senses. Of
course I leave out here the fact that it is almost at all times
visible to the eye, but there are differences of opinion as to the
effect of that portion which is visible.

At the same time it must not be forgotten that there are
advantages in towns which cannot be obtained out of them
by the most of people^-dryness caused by good drainage,
and the cleanness of good sewerage.

As I said before, I have nothing which I can call actually
new to bring forward here, but it does still present some
novel feature. The air was not examined as such, because I
had not proper conveniences for the experiments, and I was

212

ON THE AIR AND RAIN OF MANCHESTER.

compelled therefore merely to examine the rain. All the
rain was found to contain sulphuric acid in proportion as it
approached the town, and with the increase of acid the
increase also of organic matter.

The existence of albuminous compounds may be traced in
the rain, however carefully collected, and the still further
vestiges of living creatures, minute animalcules, may be found
also. These creatures are sufficient of themselves to shew
the existence of phosphates, whilst sulphates and lime may
be readily obtained. In examining the Thames water I
often found that the readiest way of collecting the phosphates
and magnesia was to wait for the animalcules to do it. When
the residue of the rain is burnt, an abundant evolution of
ammonia may be obtained ; but I have not ascertained the
amount, because it varies much, and I do not well feel able to
collect all the ammoniacal salts which may have existed in
the rain, as so much loss is caused by evaporation, even if
an acid is present. All results hitherto obtained must have
been approximative and too low.

This organic matter, however, is capable of decomposing
and of forming ammonia when it falls upon the ground, and
of furnishing food to all kinds of plants. There is enough
therefore to grow plants scantily, although experience shews
that there is not enough to produce a crop of any value. I
do not regard it however as the object of nature to manure
the land by rain — one more important and practical is to
purify the air ; and there is enough of evidence to shew us
that places entirely without organic matter may become
covered with it, and also to shew us that plants nourished
even by rain water only may be made to grow.

This shews also the possibility of large quantities of impure
matter being kept afloat in the air, indeed it is scarcely pos-
sible to obtain the vapour of water without some such impure
matter. The organic matter found in the rain seems to be in
perfect solution, and no doubt the more decomposed portion

ON THE AIE AND RAIN OP MANCHESTEB. 213

of it at least is entirely so, but an exception must be made
of that which is alive.

It becomes clear from the experiments, that rain water in
town districts, even a few miles distant from a town, is not a
pure water for drinking, and that if it could be got direct
from the clouds in large quantities, we must still resort to
collecting it on the ground in order to get it pure. The im-
purities of rain are completely removed by filtration through
the soil; when that is done there is no more nauseous taste
of oil or of soot, and it becomes perfectly transparent.

The presence of free sulphuric acid in the air sufficiently
explains the fading of colours in prints and dyed goods, the
rusting of metals, and the rotting of blinds.

It has been observed that the lower portions of projecting
stones in buildings were more apt to crumble away than the
upper ; as the rain falls down and lodges there and by degrees
evaporates, the acid will be left and the action on the stone
be much increased.

I do not mean to say that all the rain is acid — it is often
found with so much ammonia in it as to overcome the acidity ;
but in general, I think, the acid prevails in the town. But
even if alkaline when it falls, it becomes acid on standing,
and especially on boiling down, as the ammonia in these
cases is separated from its acid.

A specimen taken in Greenheys fields, half a mile from the
extreme south-west of Manchester, wind blowing west, had a
peculiarly oily and bitter taste when freshly caught. A per-
son to whom I gave some of it to taste, supposed it had been
put into a glass in which castor oil had been put. I had col-
lected the water in a large meat dish, which had been very
carefully cleaned, and was then set on a stand about two feet
from the ground, during the rain. Thinking it possible that
some fatty matter might have been adhering to the vessel in
spite of all my care, and not being inclined to believe that
such an amount of impurity could be found in that place, I

214

ON THE AlB AND RAIN OF MANCHESTER.

used a platinum basin, which was carefully cleaned, and, to
prevent all mistakes as to organic matter, kept red hot for
some time. There was however no difference to be perceived
from that collected in the larger vessel. The rain was very
alkaline, and contained scarcely a trace of carbonic acid.

Boiling removes all taste, and standing alone removes the
taste of the oily matter and leaves only the taste of smoke.
The smoke here shews that it was not out of the range of
chimnies, although the wind was west.

The taste was that of the flattest and most insipid water,
which could not be drunk with pleasure, independently of the
nauseous taste.

The water was very clear, but on standing it produced and
deposited a number of organic bodies of the monad kind,
small enough certainly when seen by themselves, but in
clusters large enough to be seen lying at the bottom of the
vessel.

The clear water above was a solution of organic and in-
organic substances, giving the following results : —

Organic matter 2'625 grs. per gallon.

[■ -875 1
Inorganic " J 1'33 - in three experiments,

[2-100 j

By boiling the carbonate of ammonia is driven off, at
least this seems the only way of accounting for the loss of
alkalinity.

On burning the residue after evaporation, ammonia is given
off, and a strong smell of feathers, characteristic of albumi-
nous compounds.

The ash is alkaline, with fixed alkalies, like the ashes of
plants and other organic matter.

Cavendish-street, June 8th, 1851. — The taste of this water,
collected of course directly into the vessel, was the same as
that which comes from the roofs of the houses* The taste is
nauseous and chiefly of smoke.

ON THE AIR AKD RAIN OF MANCHESTER.

215

It contains many of the green monads, singly and in groups.
These increased immensely, and were in numbers much greater
than in the field rain. There were also some lengthened bodies
somewhat resembling the gallionella, but I cannot speak with
certainty of the species.

This water is acid, and on boiling becomes very acid, until
it may be readily tasted as sour.

The residue when burnt gave off ammoniacal vapours, and
shewed also the presence of albuminous compounds. The
sides of the vessel were covered over with an oily or tarry
substance.

The ashes were neutral, and consisted of sulphates; sul-
phate of lime and soda being amongst them.

These two specimens are characteristic of the places ; they
are not extreme points by any means. One is not very far in
the town, and the other is not very far out of the town. I
am sorry I have not obtained extreme cases, but the difference
is sufficient as a point to start from. The one leaves alkaline
ash, the other neutral ash. In the fields the amount of acid
is not sufficient to neutralize the bases which are in union
with the organic matter, and the residue is therefore alkaline ;
but in the town the amount of acid is equal, or in excess;
what is in excess is driven off, and enough remains to saturate
the bases, which become then neutral salts.

The increase of amount of organic matter is not so apparent
from the table of quantities which I have drawn up ; but I
rely more on observing these living creatures, which are the
sure indications of its presence. And they shew also that if
there was not a great increase of it in the town, it was at least
in a state peculiarly organizable.

Again, Greenheys fields, on the same day. — This water has
a blackish deposit ; a few monads may be seen at once ; taste
when first got very greasy ; after standing a while this taste
becomes bitter, like rotten leaves; flat, like all the speci>

216

ON THE ATR AND RAIN OF MANCHESTER.

mens ; sickly taste begins when the greasy and bitter tastes
are gone.

Alkaline also ; alkalinity lost by boiling.

Nitrogenous fumes obtained on burning the residue.

Residue as before, alkaline.

Timperley, six miles distant. — Abundance of green matter
at the bottom of the glass ; an immense amount of green mo-
nads, mostly separate, but some in clusters.

Gave off alkaline fumes when the residue from evaporation
was burnt.

Ash then strongly alkaline.

This water was strongly alkaline, and was farthest from the
town ; it had, however, a great deal of organic matter in it —
as much as any — so that the acid seems so far to be a surer
guide to the neighbourhood of the town.

Park-street, outside of the town, south-west. — Matted
confervas appeared in this specimen, on standing, with many
green spots stationary and in motion.

The water alkaline, but acid on boiling.

The ashes neutral.

We are here therefore still within the town influence, but
it appears that in the outskirts of the town the acid is neu-
tralized in a great part with ammonia, as the rain does not
become acid until that is driven off.

We may therefore find easily three kinds of air, — that with
carbonate of ammonia in the fields at a distance, — that with
sulphate of ammonia in the suburbs, — and that with sulphuric
acid, or acid sulphate, in the town.

I need not minutely describe each specimen which I
collected ; there is much similarity when from the same
district.

ON THE AIR AND BAIN OF MANCHESTER. 217

AMOUNT OP INORGANIC MATTER IN A GALLON.

Greenheys 875 2.100

Cavondish-street, 8th June 1 .050

9th " 5.6

Park-street 21

Timperley 3,937

Greenheys fields 2.1

Cavendish-street again 2.8

Moss-side 8

Greenheys fields 2.333

Greenheys again 1.33

Cnvendish-street, 5,000 grs. used 3.010

ORGANIC MATTER.

Greenheys 56

Cavendish-street, June 1.960

Park-street 4.200

Greenheys fields 2.799

Moss-side 1.45

CHLORINE IN A GALLON.

Greenheys 47712

Cavendish-street, June 8th, 1851 3976

" " 9th 5300

Moss-side 896

SULPHURIC ACID IN A GALLON.

Greenheys 0.3840

Cavendish-street 1.0752

1.0752

" 5972

Greenheys fields 4480

Park-stroet-outskirts 5376

5376

6740

Timperley 2.2400

Moss-side fields 8960

Note. — There is an unaccountable quantity at Timperley. This requires
explanation. The wind was from the west, and violent. Did it receive its im-
pjirity from an upper current ?

The quantity of acid was determined by comparing prepared solutions. I
doubt if it is very accurate with baryta, and do not intend to use it again.

2f

219

LIST OF BOOKS

PRESENTED TO THIS SOCIETY FROM DECEMBER IOth, 1851,
TO NOVEMBER 2nd, 1852.

Donors.

LlTERAKY & PhTLOSOPHICAL

Society of Liveepool.

Smithsonian Institution,
Washington.

Titles of Books.
Proceedings of the Literary and Philosophical
Society of Liverpool, Vol. VI.

Fourth and Fifth Annual Reports of the Board
of Regents of the Smithsonian Institution.

Report of the Smithsonian Institution on the
history of the Discovery of Neptune, hy Benj.
Abthorp Gould, jun.

Smithsonian Reports — Notices of the Public
Libraries in the United States, by Charles
C. Jewett.

Forster and Whitney's Report to Congress.

Patent Office Repoi-t for America, 1848.

Smithsonian Contributions to Knowledge, Vol. II.

«< » " Vol.111.

'• " " Vol. IV.

First Appendix to the Third Volume of Smith-
aonian Contributions to Knowledge, "An Ephe-
meris to the Planet Venus for 1852," by Sears
C. Wai.ker.

History of the Condition and Prospects of the
Indian Tribes of the United States, by H. R.
ScHooLCROFT, LL.D. Illustrated by Captain
Eastman, U.S.A. First Volume.

Smithsonian Reports on the recent Improve-
ments in the Chemical Arts, by Booth and

MORFIT.

Directions for Collecting Specimens of Natural
History.

Registry of Periodical Phenomena.

List of Books published by the Smithsonian
Institution.

220

LIST OF BOOKS PRESENTED TO THIS SOCIETY.

Donors,

Smithsonian Insiitution,
Washington.

Sent theough the Smith-
sonian iNSTITtrriON.

Superintendent of
Weights and Measures.

Surgeon-General of the
United States.

Commissioner of Patents.

Commissioner of Indian
Affairs,

The American Association
FOR THE Advancement of
Science.

J. N. Nicollet.

L'Observatoire Central
DE RussiE.

Mb. James Higgin.

Museum of Practical Geo-
logy, London.

Titles of Books.
List of Foreign Institutions with which the
Smithsonian Institution is in correspendence.

Abstract of the Seventh Census of the United
States.

American Zoological, Botanical, and Geological
BibUography, for the year 1851, by Charles

GiRARD.

Report on Sugars and Hydrometers, by Professor
R. S. Mc. CuLLOCH. 1848.

Report of the Commissioner of Patents for 1850.
Part 1st — Mechanical
Pan 2nd — Agricultural

Tables used with the Custom-house Hydrometers.

Army Meteorological Observations for Twelve
years, l;831-42.

Second and Third Reports on Meteorology to the
Na\7 Department, by Professor J. P. Espy.
1851.

United States. Patent Laws.

Rules for obtaining Patents in the United States.

History, Condition, and Prospects of the Indian
Tribes of the United States, by H. R. School-
CROFT, LL.U. Illustrated by Captain Eastman.
Vol. II.

Proceedings of the American Association for the
Advancement of Science ; fourth meeting, 1850.

Hydrographical Basin of the Upper Mississippi,
from Astronomical Barometrical Surveys and
Information, by J. N. Nicollet.

Annales de L'Observatoire Physique Central de
Russie, par A. T. Kupffeh. Nos. 1 , 2, and 3,

1848.

Compte Rendu Annuel, par A. T. Kupffer. St,
Petersbourg. 1850.

Comptes Rendus, for 1850-51.

Introductorj' Lectures — by Professors Percy, W,
W. Smyth, Ramsay, Forbes, Playfaih, and
Sir H. de la Beche.

LIST OF BOOKS PBESENTED TO THia SOCIETT.

221

Donors.
Scottish Society of Arts.

Institute of CrviL Engin-

EEBS.

EoYAii SociETy OF Edin-
burgh.

Royal Society.

M. Emanuel Liais (the
Author.)

Cambridge Literary and
Philosophical Society.

Matthus Dunk, Esq. (the
Author)

Jos. Dickenson, Esq.

Edinburgh Astronomical
Society.

Society of Antiquaries.

W. Hopkins, Esq., Cam-
bridge.

EcoLE DBS Mines.

Physikalische Gesell-
schafft, Betlin,

Professor W. Thomson,
Glasgow, (the Author.)

Titles of Books.

Transactions of the Royal Society of Arts, Vol.
III., Part 6.

Proceedings of the Institute of Civil Engineers,
up to Ist Part of, 1850-51 ; with List of the
Members.

Proceedings of the Eoyal Society of Edinburgh,
1851-52.

Transactions, Vol. XX., Part 3.

Philosophical Transactions, Part 1, 1851.

Proceedings of the Boyal Society (continued)

L'Eclipse au 28 Juillet, 1851.

Addition k un Memoire intituli^ Theorie Mathe-
matique des Oscillations du Barometre.

\
Transactions of the Cambridge Literary and Phi-
losophical Society, Vol. IX., Part 2, 1851.

Report of Matthias Dtjnn, Esq., Inspector of
Coal Mines, 1851.

Report of Jos. Dickenson, Esq., Inspector of
Coal Mines, 1851.

Edinburgh Astronomical Obsen'ations, Vol. X.,
1844, 1845, 1846-47.

Proceedings of the Society of Antiquaries, 1849-52*

Atchaeologia, VoL XXXIII. and Vol. XXXIV.—
2 Parts.

Address to the Geological Society by Professol'
Hopkins, President, Februarj', 1852.

Annales des Mines, to the 2nd Livr. of 1852,
Fortschritte der Physik, 4th year, by Karsten.
Mechanical Theorj' of Electrolysis, by W. Thom*

Theory of Magnetic Induction in Crystalline and
Non-Crystalline Substances, by W. Thomson.

Mechanical Theory of Magnetism.

Dynamical Theory of Heat, with Numerical Re-
sults deduced from Mr. Joule's Equivalent oi
a Thermal Unit, by W. Thomson.

222 BEQUESTS TO THIS SOClETi

BEQUESTS.

A Silver Inkstand, which had been presented to Dr. Dalton by the
Mechanics' Institution, bequeathed by the late Petee Claee, F.R.A.S., Vice-
President of this Society.

A Portrait of Peter Claiie, Esq., bequeathed by the late . Samuel
Elsworth Cottam, F.E.A.S.

THE COUNCIL

OF THE

ilitctarg antr ^^tlosopi^ical Soctetg of

SESSION 1852-53.

JOHN MOORE, F.L.S.

WILLIAM FAIRBAIRN, F.R.S,, Instit. Nat. Paris. Corresp :

M. Instit. C.E.
JOSEPH CHEESEBORO.UGH DYER.
EATON HODGKINSON, F:R.S.;TI;R.I.A., F.G.S., &c.
JAMES PRESCOTT JOULE, F.R.S., &c.

Sittvttavita.

REV. HENRY HALFORD JONES, F.Rjl.S.
ROBERT ANGUS SMITH, Ph. D., &c.

GEORGE WAREING ORMEROD, M.A., F.G.S.

HbXAXlAtt.
E. W. MAKINSON, M.A.

®f tijr ©ountiL

THOMAS HOPKINS.

RICHARD ROBERTS, M. Inst. C.E.

LAURENCE BUCHAN.

EDWARD WILLIAM BINNEY.

PROFESSOR W. WILLIAMSON, F.R.S.

HENRY BOWMAN.

AN

ALPHABETICAL LIST OF THE MEMBERS

OF THE

LITERARY AND PHILOSOPHICAL SOCIETY
OF MANCHESTER,

OCTOBER 19th, 1852.

Date of Election,

James Ainsworth January 25th, 1805

Ealph F. Ainsworth, M.D April 30th, 1839

Thomas Ashton, M.D October 29th, 1821

Thomas Ashton, Hyde August 11th, 1837

John Atkinson January 27th, 1846

W. H. Ash April 17th, 1849

Richard Parr Bamber October 19th, 1821

Robert Barbour January 23rd, 1824

Joseph BaiTatt April 19th, 1842

John Frederic Bateman, M. Inst. C.E January 21st, 1840

Thomas Bazley January 26th, 1847

"W illiam Bell January 26th, 1847

James Bevan January 23rd, 1844

Edward William Binney January 25th, 1842

Alfred Binyon January 26th, 1838

Richard Birley April 18th, 1834

James Black, M.D., F.G.S April 30th, 1839

Henry Bernoulli Barlow January C7th, 1852

John Blackwall, F.L.S January 26th, 1821

Henry Bowman October 29th, 1839

Edward Brooke April 30th, 1824

W. C. Brooks, M.A January 23rd, 1844

2g

226

Dat^ of Election.

Henry Browne, M.B January 27th, 1846

Laurence Buchan November 1st, 1810

John Burd January 27th, 1846

Bev. K. Bassnett, M.A April 17th, 1849

Frederick Grace Calvert, M.R.A.T January 26th, 1847

John Young Caw April 15th, 1841

David Chadwick April 20th, 1853

Henry Charlewood Januarj' 24th, 1832

Charles Clay, M.D April 15th, 1841

Charles Cleminshaw April 29th, 1851

Eev. John Colston October 29th, 1850

Thomas Cooke April 12th, 1838

Samuel Crompton April 29th, 1851

James Crossley January 22nd, 1839

Joseph S. Crowther January 25th, 1848

Charles Cumber November 1st, 1833

Matthew Curtis April 18th, 1843

John Benjamin Dancer April 19th, 1842

Samuel Dukinfield Darbishire January 25th, 1822

Rev. John Davies, M.A January 21st, 1851

James Joseph Dean November 15th, 1842

Thomas Dickson January 27th, 1852

Joseph Cheeseborough Dyer April 24th, 1818

Frederick Nathaniel Dyer April 30th, 1850

The Eight Hon. the Earl of Ellesmere, F.G.S April 15th, 1841

Thomas Fairbaim April 30th, 1850

William Fairbaim, F.R.S., M. Inst. C.E., Inst. Nat. Paris.

Corresp October 29th, 1824

W. A. Fairbaim October 30th, 1849

Octavius Allen Ferris .January 26th, 1847

David Gibson Fleming January 25th, 1842

William Fleming, M.D April 18th, 1828

Richard Flint October 31st, 1818

Edward Frankland, Ph. D., F.C.S., Professor of Chemistry,

Owen's CoUege April 29th, 1851

Robert Finlay, B.A., T.C.D., Professor of Mathematics,

Manchester New College October 21st, 1851

Rev. William Gaskell, M.A January 21st, 1840

227

Date of Election.

Samuel Giles April 20th, 1836

Thomas Glover January Slst, 1831

John Goodman, M.D January 25th

John Gould April 20th

John Graham August 11th

Robert Hyde Greg, F.G.S January 24th

William Eathbone Greg April 26th.

Eobert Philips Greg October 30th

John Edgar Gregan January 25th

John Clowes Grundy January 25th

Robert Greaves January 27th

Rev. Robert Halley, D.D April 29th

Richard Hampson January 23rd,

John Hawkshaw, F.G.S., M. Inst. C.E January 22nd

WiUiam Charles Henry, M.D., F.R.S October 31st

Sir Benjamin Hej'wood, Bart., F.R.S. January 27th

James Haywood, M.P., F.R.S. & G.S April 26th

James Higgins April 29th,

Peter Higson October 31st

John Hobson January 22nd.

Eaton Hodgkinson, F.R.S., M.R.I A., F.G.S., &c January 21st,

James Piatt Holden January 27th

Thomas Hopkins January 18th

Henry Houldsworth January 23rd,

James Higgin .April 29th

Paul Moon James » January 27th

John Jesse, F.R.S., R.A.S., & L.S January 24th

Rev. Henry Halford Jones, F.R.A.S April 21st,

Joseph Jordan October 19th

James Prescott Joule, F.R.S., &c January 25th

Benjamin Joule, jun April 18th

William Joynson January 27th

Richard Johnson April 30th

Alexander Kay October 30th

Samuel Kay January 24th

John Kennedy April 29th

John Lawson Kennedy January 27th.

Richard Lane April 26th

William Langton April 30th

1842

1847
1837
1817
1833
1849
1848
1848
1852

1845
1844
1839
1828
1815
1833
1845
1848
1839
1820
1846
1823
1824
1851

1837
1823
1846
1821
1842
1848
1848
1850

1818
1843
1803
1862

1822
1830

228

Date of Election.

Joha Rowson Lingard January 26th, 1847

Thomas Littler January 27th, 1825

John Lockett January 25th, 1842

Joseph Lockett October 29th, 1839

Benjamin Love Apiil 19th, 1842

Joseph Leese, jun April 80th, 1850

Edward Lund April 30th, 1850

Isaac Waithman Long, F.R.A.S January 27th, 1852

James M'Connel October 30th, 1829

William M'Connel April 17th, 1838

Alexander Mc. Dougall April 30th, 1844

John Macfarlane January 24th, 1823

Edward William Makinson, M.A October 20th, 1846

The Eight Rev. the Lord Bishop of Manchester, D.D.,

F.E.S., F.G.S April 17th, 1849

Robert Manners Mann January 27th, 1846

James Meadows April 30th, 1830

Thomas MeUor January 25th, 1842

WiUiam MeUor January 27th, 1837

John Moore, F.L.S January 27th, 1815

L. A. J. Mordacque October 29th, 1830

David Morris January 23rd, 1849

George Murray January 27th, 1815

Alfred Neild January 25th, 1848

William Neild April 26th, 1822

John Ashton NichoUs, F.R.A.S January 21st, 1845

William Nicholson Januaiy 26th, 1827

Jaiues Emanuel Nelson ; January 27th, 1852

George Wareing Ormerod, M.A., F.G.S January 26th, 1841

Henry Mere Ormerod April 30th, 1844

John Owen April 30th, 1839

George Parr April 30th, 1844

John Parrj' April 26th, 1833

George Peel, M. Inst. C.E AprQ 15th, 1841

Archibald Prentice January 22nd, 1819

Joseph Atkinson Ransome, F.R.C.S April 29th, 1836

Thomas Ransome January 26th, 1847

Rev. John Gooch Robberds April 26th, 1811

Richard Roberts, M. Inst. C.E January 18th, 1823

229

Date of Election.

Samuel Robinson January 25th

Alan Eoyk January 25th

Samuel Salt April 18th

Michael Satterthwaite, M.D .January 26th

Edward Schunck, Ph. D., F.R.S., &c January 25th

Salis Schwabe » April 20th

John Sharp October 28th

John Shnttleworth October 30th

Joseph Sidebotham April 20th,

George S. Fereday Smith, M.A., F.G.S January 26th

Robert Angus Smith, Ph. D., F.C.S April 29th,

Edward Stephens, M.D January 24th,

Ferdinand Sichel April 29th

Peter Spence April 29th

Archibald Sandeman, M.A., Professor of Mathematics, Owen's

College April 29th

Thomas Standring , January 27th

James Stephens April 20th,

Daniel Stone, jvm January 23rd,

Robert Stuart » .January 21st.

Rev. John James Tayler, B.A January 26th

David Thorn April 20th

John Thorn January 27th

James Aspinal Turner April 29th

Thomas Turner, F.E.C.S April 19th,

Absalom Watkin i ; . .January 24th

Joseph Whitworth January 22nd,

Matthew A. Eason Wilkinson, M.D January 26th

William James WiLson, F.R.C.S April 29th

Gilbert Winter November 2nd

George Bancroft Withington January 21st,

William Rayner Wood - .January 22nd,

George Woodhead April 21st,

Edward Woods April 30th

Robert Worthington, F.R.A.S ; April 28th

James Woolley November 15th,

William Crawford Williamson, F.R.S., &c., Professor of

Natural History, Owen's College April 29th,

Joseph St. John Yates ; January 26th

James Young October 19th,

1822
1842

1848
1847
1842
1847
1824
1835
1852
1888
1845
1834
1851
1851

1851

1852
1847
1849
1814

1821
1852
1846
1836
1821

1823
1832
1841
1814
1810
1851
1839
1846
1839
1840
1842

1851

1841
184f

280

HONORARY MEMBERS.

Hev. William Turner, Manchester.

i)r. A. P. Erman, Berlin.

Very Rev. William Buckland, F.R.S., Instit. Nat. Sc. Paris. Corresp., &c.

Eev. Adam Sedgwick, M.A., F.R.S., Hon. M.R.I.A., &c., Cambridge.

General Sir Thomas MakdougaU Brisbane, Bart., F.R.S., Hon. M.R.I.A.,

Instit. Nat. Sc. Paris. Corresp., &c., Makerstoun, Kelso.
Eev. William Venables Vernon Harcourt, M.A., F.R.S., Hon. M.R.LA.,

F.G.S., York.
Rev. William Whewell, B.D., F.R.S., Hon. M.R.I.A., F.R.A.S., &c., Cambridge.
Sir William Hamilton, Bart., Dublin.
Baron Von Liebig, Munchen.
Eilert Mitscherlich, Berlin.
Paul Frisiani, Milan.
Sir John Frederick William Herschel, Bart., D.C.L., F.R,S.L.&E., &c. &c.,

Instit. Nat. Sc. Paris. Corresp.
Michael Faraday, Esq., D.C.L., Hon. Mem. R.S. Ed., Instit. Nat. Paris. Socius.
George Biddell Airy, Esq., MA., D.C.L., F.R.A.S., F.R.S., &c. &c., Eoyal

Observatory.
Sir David Brewster, F.R.S. L.&E., Instit. Sc. Paris. Socius, Hon. M.R.I.A.,

F.G.S., F.R.A.S., (fee, St. Andrew's.
Very Rev. George Peacock, D.D., r.R.S., F.G.S., F.RA.S., Ely.
Fraufois Jean Dominique Arago, Pa7-i8.
Jean Baptiste Biot, Paris,
Baron Alexander Von Humboldt, Berlin.
Peter Barlow, Esq., F.R.S., r.R.A.S., Hon. M.P.C.S., Instit. Nat. Sc. Paris.

Corresp., Woolwich.
Eev. Henry Moseley, M.A., F.R.S., Wandsworth,
Louis Agassiz, Cambridge, Massachussets.
Lieut.-Colonel Edward Sabine, R.A., F.R.S.V.P., F.R.A.S., <fec.
Jean Baptiste Dumas, Paris.
Sir Roderick Impey Murchison, G.C. Sc. S., M.A., F.G.S., Hon. M.R.S. Ed.,

R.I.A., <fec. &c.
Richard Owen, Esq., M.D., LL.D., F.R.S., Hon. M.R.S. Ed., Instit. Nat. Sc.

Paris. Corresp., &c. &c.
John Couch Adams, Esq., F.R.S., F.R.A.S., <fec., Cambridge.
W. J. J. Le Verrier, Paris.
J. R. Hind, Esq., Regent's Park.
Rev. Joseph Bosworth, LL.D., F.S.A., F.R.S., &c.
Robert Rawson, Esq., Portsmouth.

231

Bennet Woodcroft, Professor, University College.

William Thomson, Professor, University, Glasgow.

Lyon Playfair, C.B., r.R.S., (fee. Museum of Economic Geology.

George Gabriel Stokes, MA., <fec. &c., Cambridge.

Eev. Thomas Penyngton Kirkman, M.A., &c., Croft Rectory, near Warrington.

CORRESPONDING MEMBERS.

Eev. John Kenrick, M.A., York.
Jonathan Otley, Esq., Keswick.
Peter Mark Roget, M.D., F.il.S., F.G.S., r.R.A.S., &c. &c., Busselt-square,

London.
John Fletcher Miller, Esq., Whitehaven.
Rev. Robert Harley, Blackburn.

William Thaddeus Harris, Esq., Cambridge, Massachussets.
Peter Pincoffs, M.D., Dresden.
Henry Hough Watson, Esq., Bolton.
John Mercer, Oakenshaw.
M. Girardin, Paris.

Cayi & Seteb, Printers, Palatine Buildings, Hnnf s Bank, Manchester.

tt

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