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notch, a, the pin is disengaged from the gab in at the end it lifts the rack by its own movement,, dication of pleasure till the song was finished, the eccentric-rod.

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5. A screw-clamp. On turning the handle the screw thrusts upward against the holder, which, operating as a lever, holds down the piece of wood or other material placed under it on the other side of its fulcrum.

6. Scroll-gears for obtaining a gradually increasing speed.

7. A variety of what is known as the "mangle wheel." In this one the speed varies in every part of a revolution, the groove b, d, in which the pinion-shaft is guided, as well as the series of teeth, being eccentric to the axis of the wheel.

8. Another kind of mangle-wheel, with its pinion. With this, as well as with that in the preceding figure, although the pinion continues to revolve in one direction, the mangle-wheel will make almost an entire revolution in one direction and the same in an opposite direction; but the revolution of the wheel in one direction will be

slower than that in the other, owing to the greater

radius of the outer circle of teeth.

and follows on the other side.

14. Another form of mangle-rack. The lantern-pinion revolves continously in one direction, and gives reciprocating motion to the square frame, which is guided by rollers or grooves. The pinion has only teeth in less than half of its circumference, so that while it engages one side of the rack, the toothless half is directed against the other. The large tooth at the commencement of each rack is made to insure the teeth of the pinion being properly in gear.

15. A mode of obtaining two different speeds on the same shaft from one driving-wheel.

THE EAR-ITS USES AND ABUSES.
BY DR. USSHER.

(Continued from page 6.)
NOME of my readers may remember that I told
them on a far back occasion how a pet

SOME

canary of mine, since defunct, was very partial to my clarionet, seeming to derive comfort from a 9. Another mangle-wheel. In this the speed plaintive air, and eyed me from his perch, but at is equal in both directions of motion, only one circle of teeth being provided on the wheel. With once sought the bottom of his cage if I played a all of these mangle-wheels the pinion-shaft is loud, quick measure. His demise took place one guided and the pinion kept in gear by a groove day at dinner time, to the inexpressible grief of

in the wheel. The said shaft is made with a

universal joint, which allows a portion of it to have the vibratory motion necessary to keep the pinion in gear.

10. A mode of driving a pair of feed-rolls, the opposite surfaces of which require to move in the same direction. The two wheels are precisely similar, and both gear into the endless screw which is arranged between them. The teeth of one wheel only are visible, those of the other being on the back or side which is concealed from

when it uniformly returned to the dovecot." These
quotations are full of interest. You all know the
story of the watchful geese in the Roman Capi-
tol. Throughout creation you will come across
people as diverse in their hearing as in their
tastes; some cannot for the life of them turn a
tune, and others will twist it and torture your
ears by such wretched discords that escape is im-
possible and endurance a virtue-others can't
abide it; of them I would say, "Shun that man
or woman who dislikes to hear music or the
voice of a child!" And what is more musical than
the unrestrained laugh of a coterie of little ones?
It is a happy power-the laugh of the maiden is
contagious, and if she is ringing the silver bell of
her voice it is a paan of victory, and reminds me
of a dear old song:

Toujours gai, toujours gai,
Always meet a smile half-way,
Always meet a smile half-way,
And follow my example.

remarkable for containing in its walls the glands
The passage to the drum of the ear is chiefly
furnishing the wax or cerumen, the use of which
may be to entangle such small foreign bodies as
would go in, or the too adventuresome fly. This
much is certain: I have over and over again, after
removing a hard plug, the accumulation it may
be of years, found ants, flies, &c., in the body of
it; and the wax must have a bitter taste, for no
leech will cross it, nor will it adhere to the skin
until it is perfectly well cleaned of every portion

of ear wax.

one of my little ones, whose sobs refused comfort, deriving a post satisfaction from the decent interment of the bird within sight of the garden window. "The faculty of imitating sounds possessed by certain birds proves that the hearing must be exceedingly delicate, and though we suspend our belief of the great musical talents which some birds are said to have derived from education, we find many well attested instances of a delicate ear in species by no means remarkable for vocal execution." Madame Piozzi gives an account of a tame pigeon, which answered by gesticulation to every note of a harpsichord. As 12. What is called a "mangle-rack." A con- often as she began to play, the pigeon hurried to tinuous rotation of the pinion will give a recipro- the concert with every indication of rapturous cating motion to the square frame. The pinion-delight. A false note produced in the bird evishaft must be free to rise and fall, to pass round the dent tokens of displeasure, and if frequently rejection of a stream of water into the ear, and

view.

11. The pinion, B rotates about a fixed axis and gives an irregular vibratory motion to the arm carrying the wheel, A.

guides at the ends of the rack, This motion may be modified as follows:-If the square frame be fixed, and the pinion be fixed upon a shaft made with a universal joint, the end of the shaft wi describe a line similar to that shown in the drawing around the rack.

13. A modification of 12. In this the pinion revolves, but does not rise and fall as in the former figure. The portion of the frame carrying the rack is jointed to the main portion of the frame by rods, so that when the pinion arrives

peated, it lost all temper, and tore her hands. "A
no less remarkable instance of the effect of music
on a pigeon is related by Lockman in his reflec-
tions on operas, prefixed to his musical drama of
Rosalinda. Being in the house of a Cheshire
gentleman whose daughter was a fine performer
on a harpsichord, he observed a pigeon, which
whenever the young lady played the song of
'Speri Si,' in Handel's opera of Admetus,' would
descend from an adjacent dovecot to the room
window where she sat, and listen with every in-

The colour varies from pale straw, as darkness of mahogany and the hardness of old in the infant, and of a honey consistence, to the india-rubber. I have often taken an hour for its removal with the result of restoring hearing. And here let me make a digression on the common and indiscriminate use of the syringe. If there is pain in the ear it should not be thought of; great injury as well as intolerable agony might result. Should the ear passage be impacted the speculum is of no use, and a cautious removal of the plug is all the more necessary, for it may become moulded to the drum, and even inflame it. I have seen an old person faint from the violent inviolent cough or vomiting may be equally unpleasant. One portion of the ear passage is so intolerant of touch that a probe moved over it will cause the sensation of nausea; why, I believe anatomists are ignorant of, although compelled to accept the fact they cannot explain. The tube of the ear in most persons is not straight, and it becomes necessary to stretch the auricle backwards and upwards to see the membrane; some, on the contrary, have the passage so large that the membrane of the drum is seen

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without difficulty. The direction of the meatus, cious enough in all conscience, has his external however, as long as there are people who like seems to be for the facility of, catching sounds, ear passage expanded from behind into a circular such devices they will be paraded. It requires a addressed as they usually are to the face. In aperture, and his ungainly appropriations are nice sense of touch to be able to hit the passage animals, where hearing is necessary for their thus favoured. To strengthen the assertion of with a proper catheter, the bubble heard being safety, things are otherwise ordered; take the the hare's deficient hearing in advance of her, the your test of success. Attached to the drum memhare for example, Fig. 9, and also in the pole-story is told of one pursued by greyhounds along brane is part of one of the chain of ear bones, a cat, Fig. 10. Our ear passage is not of uniforma turnpike road; a woman was approaching im- truly wonderful structure, ever on the move; no calibre, but wider or funnel-shaped below, so mediately in front of her, she knelt down and the noise of clockwork here, balanced to a nicety, that in using the speculum it is only possible to hare ran fairly into her apron, which was stretched and retained in that balance by ligaments or binds see a portion at a time. The bony passage is in-out to receive her. This circumstance clearly to the bone walls adjacent. Every vibration is complete in the young, and in their case we get a proves that poor puss was much more occupied conveyed by this swinging chain of ossicles, or better view of the parts; what we see may be with dangers from behind, and heedle-s of those little bones, to the fenestrum, or window of the briefly described, and Fig 1 will convey some before her; she preferred, however, to yield her- vestibule, the fourth bone, or the third, according idea thereof. The first thing that attracts you if self to her who is ever the refuge of the perse- to some, closing that opening with a stopper you are sharp-eyed is a spot of white and a line of cuted and oppressed, and we may hope for the shaped like a stirrup. The hammer bone, Figs. white where the handle of the malleus or hammer credit of her sex she did forego the temptation 2, 3, and 4, acts on its neighbour the anvil, and bone is attached as if sewn to the membrane; you for once of roast hare and currant jelly. You this in turn on the stirrup, which is supposed to next perceive that the light shines off one part know, of course, that in the martial instrument be a compound bone. You can easily imagine that is higher than the rest, and if you look closely of percussion, provision is made for bracing up that if one of these bones was to be dislocated or and in a good light having a suitable ear for ob or tightening the drum-head. Well, the ear is servation, you may possibly be gratified to see provided with a tensor tympani muscle or one part of it vibrate; to do this, however, you stretcher of the drum, and as the hole in the inmust possess a Brunton's speculum, which magni-strument is supposed to be an air hole, so our fies the object, and a first-rate light. In colour cavity of the drum is supplied with one. Some the drum membrane is a mother of pearl white, contend that there is no analogy, and that the air like thin gold-beater's skin. It readily inflames, sent through the Eustachian tube from the throat then assumes a pink colour, at all times sensitive is to counterbalance the atmosphere and prevent to the touch, the slightest pressure causing pain concavity of the membrane. This tube, called and sickness. I believe it was Sir A. Cooper who after one Eustachius, opens into the throat beconceived the idea of puncturing the membrane, hind the soft palate, and performs a most iman operation that would require the nicest touch, portant function in hearing, for its closure is foland, after all, of questionable utility. Although lowed by deafness; its calibre is small, although surgeons might be numbered by the thousand, the opening in the bell-shaped extremity of the few have ever taken the trouble to see the ear-throat is large and wide; if the lining coat of dram, and I have seen some who considered it is inflamed, easy closure results, or it may be themselves very intelligent observers, direct the rendered more or less impervious by mucus filling tube of the speculum to the wall of the meatus, and it up. To remedy this defect a Eustachian cadescribe what was out of sight. Fine hairs line the theter or tube is devised to pass by the floor of passage, a cheveaux de frise in the face of an in- the nose into the bell muscle, and is connected trader. The adaptation of means to end is remark-with an air reservoir exhausted and closed by a able, and to be traced everywhere in nature; for in-stop cock; the connection being established, a jet stance, the ear passage in the owl is high up, just of air is forced into the cavity of the drum. In where he wants it-the hare's is directed backwards two instances death has followed the use of this with a long canal and highly movable ear, so that puss may be a match for her pursuers; the reverse obtains in the polecat, who follows his nose," and so deaf are they to what goes on at their back, that a story is told of a farmer who in trying to shoot one missed fire five or six times, and not a move was apparent on the part of the polecat until he was turned out of ie. The fox, preda

elaborate machine, and its employment is per-
fectly unnecessary, for if you inflate the cheeks,
having stopped the nostrils with a finger and
thumb, you may fill the cavity if the canal is per-
vious, and the bursting of a bubble of air is audi-
ble to the stethoscope of a listener. Catheters
and probes are sold by the boxful to go into this
passage, but they are too large to gain admission;

thrown out of its joint, what mischief would ensue; the outer membrane of the drum is often destroyed, and impaired hearing results. That the ear bones are not an absolute essential of the hearing organ is evidenced by their absence in fishes; and in man the foramen ovale may be at times seen through the disrupted membrana tympani, and yet the relic of hearing remains, of course useless if the liquor Cotunnii (called after Cotunnus, an anatomist) is evacuated. A broken external membrane may be replaced by an artificial drum of Yearsley's, a neat little disc of indiarubber, wired, but if the inner membrane is gone, the "sanc um sanctorum" of the ear is invaded, and all is lost. Those of you who have seen boys lifting a stone with a leather sucker, get some idea as to the action of the artificial drum; it is the putting of a new patch on an old garment, or a patching operation like what we see on an old drum worn out in the vigorous service of a Punch and Judy proprietor.

The vestibule into which the stapes is fitted communicates with the semi-circular canals and cochlea. See Fig. 1. The auditory nerve comes through the internal passage from the brain, and is in that opening said to be in close communication with the facial nerve, a fact of the highest importance in diseases of the ear. The vestibule I might liken to the hall of a house, the oval window being the door; it has no great vestibular proportions, being about the 8th of an inch in diameter. Numerous openings for nerves and

vessels occupy the walls, and the apertures of the
semi-circular canals are there noticed; another
opening leads into the cochlea, which has been
aptly compared to a winding staircase or a whelk
shell. Figs. 5 and 6. Two of the semi-circular
canals join at their extremities. The upper dia-
meter is about the 20th of an inch; the lower
part has a dilatation, or ampulla, on it. One of
the canals is horizontal, the other perpendicular,
and as this mode of arrangement is widely ob-
served in nature, it is supposed that they regulate
the direction of the sound. This winding stair-
case makes two turns and a half, and is about an
inch and a half long; its central stem, called axis,
or modiolus, terminates above in a funnel-like
expansion. These several cavities have linings,
and contain fluid which appears to be useful in
the transmission of vibrations, and another fluid
or layer of peri lymph is said to exist between
the membrane and the bone proper. There is a
curious powder found in the ear called otoconia,
a compound of carbonate and phosphate of lime,
crystalline. The diameter of some of these myste-
rious grains, the use of which we are unac-
quainted with, is of an inch; they are
3000
supposed to be analogous to the otoliths or ear
bones of fish, and the presence of this otoconia in
the lower types of organisation leads to the con-
clusion that they are for hearing purposes. This
vestibule is a chamber in which the auditory nerve
is spread, and receives its impressions. It may
seem marvellous, but M. Savart states that
cession of 24,000 impulses (Carpenter), and this
probably is not the extreme limit of acuteness.
These vibrations are determined, either by a num.
ber of apertures passing a sounding pipe in a
given time, or the number of teeth caught by a
spring in the same period.

1

sounds are still audible which result from the suc

(To be continued.)

CHAPTERS ON CURIOUS CATER

PILLARS.-APRIL.

BY J. R. S. CLIFFORD.

a moth which frequently enters houses, and is as
variable as the caterpillar which produces it. This
latter also, like its brethren, lives through the
winter, but seems to feed on without cessation,
living in the roots of plants, or concealed in the
stem. When brought to view it rolls up into a
compact ring. The colour is most frequently
some tint of brown, though sometimes the ground
is yellowish-green; a number of narrow stripes
run from head to head to tail, interspersed with
black markings. When it has ceased to eat, it
scoops out a slight cell in the earth, and appears
as a moth in June and July.

The caterpillar and chrysalis shown in our

some of its habits are very curious. Indeed, much
attention has been directed to these in late years,
since the ravages committed by them on the apple
and pear trees in some Midland counties have
been serious. The parents of the numerous
broods of these ravenous rovers, which seem to
feed on almost any tree in wood or orchard, come
forth from the chrysalis state in the dreary
months of November and December; the male
moths, with semi-transparent, dull brown wings,
sitting quietly on palings through the day; the
females, which are nearly wingless, running along
the trunks and branches of trees, where they
deposit their eggs, each one usually laying 200.
The small caterpillars which emerge, begin by
gnawing the just opening buds, when great
numbers are destroyed by birds, which visit the
buds in search of them, and frequently destroy
buds on which, apparently, no caterpillars were
feeding a weakness which the gardener is in-
clined to punish severely. As the foliage be-
comes full the caterpillars of the winter moth
prepare for themselves habitations, constructed by
drawing two or three leaves together, in which
the little tenant dwells with tolerable safety,
thrusting his head a little beyond it to feed, but
rarely exposing himself entirely to view. When
disinclined to eat, he reposes with his head on
one side and partly curled round; and when a
tree or shrub haunted by them is tapped smartly,
out tumbles a host, some descending to the ground, figure are those of the Brimstone Butterfly
others swinging by silken threads.
In appear-
ance these caterpillars vary very greatly, the Gorepteryx Rhamni): the former begins to
general colour being various shades of green, or the curiously sculptured eggs are deposited at the
appear in April on the species of buckthorn;
even brown approaching to blackish, a central
stripe down the back, which marks the position beginning of the month on the tips of the young
of the alimentary canal-or long stomach, shall caterpillars lie along the mid-rib of a leaf, when at
Until they get to be of some size, the
we call it ?-being seen in all, and other fainter rest, and thus escape notice. In favourable seasons
stripes each side, more or less distinct. When
of full size, they descend to the ground, and enter arrive at their full size in twenty-five days from
they grow with great rapidity. I have had them
the earth to complete their change, and the sudden the time of emergence from the egg and in a
disappearance of them towards the end of May fortuight afterwards the brilliant butterfly comes
from this cause is striking; where a few days forth from the chrysalis. The caterpillar is of a dull
before the insect-hunter, in beating the bushes, green, curiously shagreened over with minute
shook forth thousands, only a straggler or two points, with a paler line along each side. The
appears, but the dismantled bushes do" a tale un-
fold" of what has been done by the individuals with yellow. Common as is the Meadow Brown
chrysalis, rather singular in shape, is green tinted
now reposing quietly as chrysalides.
Butterfly (Satyrus janira), its caterpillar has, as
yet, been little noticed; it must be got by stooping
down and examining the grass fields in April and
May. In the day it is usually at rest near the
bottom of some stem of grass, and when touched
falls off in a tight ring, remaining doubled up for
a good while. This is one of the caterpillars
face is rough, and also studded with scattered
which has been called rolling-pin shaped; the sur-
hairs, and on the last segment are two little points;
the colour of the body is apple-green, with a
darker stripe. The chrysalis is attached by silk
to the grass.

A rather odd caterpillar, not frequently found
by the collector, because it is most partial to
gardens and their vicinity, which he is apt to be
negligetn in hunting, is that of the Swallow-
tailed Moth (Ourapteryx sambucata), this
moth floats slowly about the hedgerows on July
which is getting of some size in April, is of a
evenings, and is easily taken. The caterpillar,
varying brown hue, and looks exceedingly like a
bit of twig which has been snapped off, and the
resemblance is kept up by little humps along the
The elder is a
back, almost resembling buds.
tree on which it often feeds, as also on fruit trees

in gardens and orchards, extending itself usually
at full length along a branch when not eating.
In June it suspends itself in a sort of hammock,
made of bits of leaves and silk intermixed, in
which it turns to a palish chrysalis, spotted with
black.

WHEN vegetation, generally, has fairly
yielded to the influences of Spring, and
almost before many of the trees have been able
to display their leaf-glories in full perfection,
a numerous and indefatigable host of insect ad-
versaries is sure to be engaged in attacking bud,
leaf, flower, or even the wood of the tree itself.
Sometimes the attack is carried on in the broad
daylight, at other times it is insidious; the ma-
rauder lurking during the day, and sallying forth
at night, leaving, however, manifest traces of the
execution done by his jaws. The first general
brood of the caterpillars, which produce our
butterflies and moths, emerge from the egg, in
great rart, during April, though a few are delayed
till May. Others, which ceased to feed in the
early chills of Autumn, and were too cautious to Amongst the night-feeding caterpillars, the
be tempted from their winter retreats by the individuals belonging to the genus Tryphaena, are
transient fine weather of March, crawl forth in to be detected at night, and are occasionally looked
the milder month of April, and, regardless of for with a lantern by those interested in the
its showers, regale themselves on the fresh doings of insects. Most of them have lived
spring leaves. "Regardless of its showers," did through the winter, and in April they ascend the
I say? Not altogether so; for many cater- trees at night and nibble the buds and young
pillars succumb to them, and will be "found leaves, retiring to the ground at early morning,
drowned" after a heavy rain fall chiefly those aud hiding amongst the short herbage. That
which have not long emerged from the egg. In of the very handsome moth, called the Broad
the gales, too, which continue some seasons to Bordered Yellow Underwing (T. fimbria), is
prevail through part of April, others are blown fond of making midnight excursions on birches
from their food-plants into roads or other posi- and sallows, where it may be rather readily
tions, where they are either readily seized by birds, found, being noticeable by its numerous mark-
or die from starvation, through being unable to ings scattered over the clay-brown velvety skin;
regain the plant or tree which yields their wonted the head is very small, shining, and mottled.
diet. So that gardeners and agriculturists have So also acts the caterpillar of the smaller and
reason to rejoice that the ravages of caterpillars, more abundant Lesser Yellow Underwing (T. ar-
at their greatest, are nothing to what they might bona), but as it rolls, when touched, into a com-
be, were all circumstances favourable to their pact ring, it often falls to the ground and is
nutriment and growth. Nor must we forget the missed. The colour and markings resemble
singular circumstance, that in addition to external those of its relative, and at certain times it ap-
enemies, every species of caterpillar has, as we rears to feed also on chickweed in the daytime.
believe, an internal enemy, in the shape of some When of adult size, it becomes a chrysalis on the
parasite, which, at a certain point in the career of
a large number of each kind, deposits its eggs
upon the skin, and the grubs produced therefrom
devour, slowly or gradually, the luckless indivi-

duals attacked.

Surely the most abundant of the April caterpillars, is that which produces the Winter Moth (Chimatobia brumata), and common as it is,

surface of the ground, and the moth appears
about a month after. The Lesser Broad Bordered
(Tjanthina), another of the family, in its cater-
pillar state, prefers to feed on garden plants of a
variety of kinds, feeding in the daytime on the roots,
and emerging from the ground at night to nibble
the leaves. The most abundant of the genus is
the well-known Yellow Underwing (T. promwba),

leaves.

aquatic places, is that which includes the Wain-
An interesting family of moths, which haunt
scot Moths, which flit to and fro, as soon as even-
ing sets in, some appearing in July, others in
August and September. The habits of the cater-
pillars are in many respects singular, most of
them living through the winter, and feeding up
in the spring. Some of these may be readily
found in April, in marshy ground, and on the
banks of streams and ditches. The Smoky Wain-
scot (Leucania impura) is a London insect, occur-
ring about the Thames, and common throughout
the three kingdoms. The caterpillar, yellowish
grey, with paler lines, feeds on different grasses,
and may be swept from them with a net. So also
does the caterpillar of the Common Wainscot
(Leucania pallens), which is full grown in April,
and is greyish-brown in colour, dotted along the
back with black, and marked with delicate longi-
tudinal lines. In the reed mace, in many places,
the larger caterpillar of the Bull-rush Moth (No-
nagria typha.) may be found, though as yet small,
since it is not full grown till July. This caterpillar
is long, and has a smooth head, and a strong
plate in the second segment, which enables it to
move with facility within the stem of the plant,
where it subsists on the pith. By a remarkable
instinet, when about to change, it cuts a circular
hole in the side of the stem, coming close to, but
not through the surface, and leaving a thin film
through which the future moth easily pushes its
way. Another lover of fens and marshes is known,
as the Fen Wainscot (Calamia phragmitidis), once
abundant near Greenwich, and still plentiful in
Cambridgeshire. The caterpillars live in the
stems of the common reed, where they may be
found near the tip in April. These are rather
maggot-like, and when removed from their re-
treats, crawl about restlessly. The head is small

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and deep black, the body dingy white, with black | required, that is, by means of the rack wheel on
dots and bristles, and a horny plate behind the its (K's) axis which acts on the rack, shown in
bead.
Unlike the preceding, when full grown, the drawing; L, strong bolt to fix the table
caterpillars quit the stem, and change to when at the proper height.
chrysalides on the ground.

Many a young collector of insects has carried home with triumph the handsome caterpillar of the Drinker Moth (Odonestis potatorin), which feeds on grass in the early morning throughout

THE WAVES.

LECTURE was delivered at the Midland

a heavy body acquired in falling through a depth equal to half the virtual depth of disturbance. The periodic tidal wave, the effect of waves upon the coast, the concentration of the energy of the wave upon being compressed into a channel, when its height became considerably increased, and the breaking up of the wave by an abrupt diminution in the depth of the water, were treated by the lecturer. In connection with the behaviour their refraction and reflection were noticed, and the lecturer, announced in conclusion, that his next discourse would be an explanation of the action of waves as regarded the stability and repulsion of ships.

the spring, but not unfrequently during the day, A Instituts, Birmingham, on the 21st uit., by of the waves upon rolling in towards the shore,

it climbs up some neighbouring twig to bask in the sunshine, leading persons to the natural, yet erroneous conclusion that it eats the plant on which it is found. This caterpillar is coated with hair, even to the feet, and is thus well enabled to defy the cold of winter. The colours are very varied, the back being blue-grey, mottled with black, with orange spots and streaks along the sides. The cocoon is formed of silk, and is of a leathery texture, and attached to a blade or two of grass. The name "drinker" was given to the species because the caterpillars have a habit of occasionally sipping the dew drops, and if kept in confinement, get on all the better if the food given them is damp, contrary to what is the case with the majority.

Mr. W. J. Macquorn Rankine, Professor of Engineering and Mechanics in the University of Glasgow, on "Waves." The lecturer said he was not going to lecture upon those classes of waves, the existance of which was inferred by means of scientific reasoning, such as light waves, nor upon that class of waves whose existence, though a matter of demonstration, was not obvious to the senses, like sound waves; but the waves upon which he was about to speak were those commonly understood as liquid waves, like the waves of the sea. The motion of such waves was a subject which possessed a great deal of scientific and practical interest, inasmuch as it was against these waves that a defence had to be provided in the shape of breakwaters and sea walls, and a knowledge of their motion and the force they exerted was of great importance in civil engiBLANE'S IMPROVED MACHINE FOR neering relating to such works. Their motion affected in an important degree the motion of vessels, the stability and resistance of ships, and the power required for their repulsion. Therefore, a knowledge of the motion and the force exerted by waves was of the greatest importance in naval architecture and ship-building. The present lecture would embrace an explanation of the nature of the motion taking place in the waves of the sea, and the force they exerted. The

MORTISING TIMBER.

THIS HIS improved machine for mortising timber, patented by G. N. Blane, of Glasgow, consists of an upright framing or standar to which the moving parts are attached. The moving parts consists of a foot lever attached by a pin joint to the lower part of the framing or standard, and from the back part of such lever

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a connecting rod passes up and is connected to another lever at the upper part of the framing or standard. This lever is carried on a centre or centres fixed in the framing or standard, and its front end is connected by links to the bar which earries the mortising tool or tools. Below the mortising tool or tools an adjustable table for carrying the timber to be mortised is situated. Fig. 1 is a front view, and Fig. 2 a side view of the machine. A, the upright framing or atandard; Al, the foot lever; A2, the upper lever which is made forked, motion being communicated from the foot lever Al to the upper lever A2 by a back red; B, spindle for the mortising tool; C, tool in spindle; D, handle for reversing the spindle and tool; E, spring catch to keep the spindle in the proper place when it is rereversed; F, gauge to move to any depth of wood and keep the wood from lifting when the spindle with the tool is rising; G, pinching pins to fix the gauge to any height; HL, screws for shifting the table in or out from I te J; K, wheel to lift the table up or down to any height

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THE MANCHESTER INSTITUTION OF

ENGINEERS.

OME three years since Mr. William W Hulse, M. Inst, C.E., and several other. eminent engineers of Manchester, perceiving the want of a good local institution for the advancement of engineering science, formed themselves into a society under the above title. The early proceedings of this institution have lately been The names of printed, and are now before us. those gentlemen who have taken an active part in the working of the institution indicate the value of its proceedings to engineers generally. A combined knowledge of the thoughts and ideas of practical men engaged in the various departments of mechanical science, helps greatly to qualify an engineer for general practice. It is to this end that such institutions are formed, and they are worthy of every support, whilst they are devoted to the mutual exchange and diffusion of the knowledge acquired by members during the pursuit of their respective branches of engineering. Turning to the "Transactions," we find the first part comprises the address of the president for 1867, Mr. George Peel of Manchester. After referring to numerous matters of interest, the President expresses a hope that it will not be long before a professorship of engineering is endowed in Owens College, and a professor appointed for instructing the pupils in that branch of scientific knowlege, which is one of the most important-in a practical point of view-to which they can apply themselves. The establishment of such a professorship would undoubtedly prove of considerable interest to all connected with engineering. The next meeting reported was occupied by a paper on dead stroke power hammers, by Mr. James Fletcher, Jun., and another on life boats and their appliances, by Mr. J. Corbett. Both subjects were fully discussed at a subsequent meeting. The remaining papers in the volume under notice are respectively on friction breaks and couplings, by Mr. T. A. Weston, aud on patent fuel, by Mr. G. W. Ommaney,

The second part of the proceedings opens with the presidential address of Mr Hulse, who is termed the father of the institution. Mr. Hulse offers some very practical remarks upon the subject of light railways. [The same volume contains no less than five papers upon the Irwell floods, with suggestions for their remedy. Two of these papers are by Mr. J. Fletcher, the others being by Mr. G. Lowry, Mr. J. Corbett, and Mr. Trapp, respectively. The proceedings for 1869 are not yet printed, but an important paper on the patent laws, read by Mr. Theodore Aston, at a meeting of the institution held on the 4th of January last, has been published. The reading of this lecturer then popularly illustrated by means of paper is peculiarly opportune at this time, as the diagrams the way in which the waves were origin-subject of the patent laws is likely to be discussed ated, by some foreign body pushing the particles in the House during the present session. In this of water in a forward direction, when they became paper, and also in the discussion which followed heaped up, which direction they communicated to its reading, and in which several gentlemen well the particles immediately beyond them; but, in qualified to deal with the question, took part, will returning to their original level, they lost their be found some sound suggestions upon the whole forward motion. The action of the wind upon subject. We have only to add that the the water formed a long ridge, which, however, institution is represented in London by Mr. W. was not a continuous advancing motion, but an Lloyd Wise, who is the honorary secretary, and alternate rising and falling of the particles. In who has promised to furnish us with copies of the the most simple kind of wave motion, the papers read at the meetings of the institution, particles of water advanced and retired, each and which, if they correspond with those that individual particle describing a circle in about a have preceded them, will prove very interesting central position, by a series of crests and troughs. to our readers. This was the motion of the long Atlantic swell, and such waves had been known to travel 2000 miles with but little diminution in size. The modification which this wave motion underwent according to the depth of water, and the production of stationary waves, were illustrated. The speed with which the crest of the wave moved forward the lecturer explained to be the same as

THE TRUE VELOCIPEDE.
R. THOMAS CLARKE, of Wilmslow,

DCheshire, has published his paper read in
September last, before the International Con-
ference held in the Crystal Palace on the "Scien-

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tific principles which should guide in the construction of velocipedes." Starting on the assumption that, with a properly made velocipede, and on level roads, an economy of time and power is gained, Dr. Clarke adverts to the delusion entertained by many mechanics, that power may be created by mechanical aids. Our subscribers are tolerably familiar with some of the contrivances produced by such personsmachines with any number of toothed wheels and pinions, each additional complication entailing a loss of power rather than a gain. In the construction of, bicycles and other locomachines, the principles to be chiefly borne in wind and acted on are safety, simplicity, and eapness. The medium must be sought between Hightness and strength, the loss by friction must be reduced to the lowest point, and the power be applied to the wheel as directly as possible. As also there are two sets of independent muscles in the human body-one below and one above the waist-it is essential that, in a properly constructed machine, the two sets shall be able to act either independently or combined. These and other objects appear to have been kept in

view by Dr. Clarke in the construction of the machines invented by him, drawings of which are given with his book, and which we reproduce.

THE TRUE VELOCIPEDE.

drums or pulleys on nave; & handles to pulleys; | in diameter, its bed twenty-one and a half feet
treadle for foot in down stroke; m seat for men below the surface of Broadway. The mouth of
resting. Figs. 5 and 6 are plan and side views the tunnel opens directly into a large underground
of a new bicycle. In this machine, according to apartment, one hundred and twenty feet in
the inventor, all complications are weeded out as length, fitted up in good style, for the purposes
far as possible. It can be taken to pieces in a few of a waiting and reception station. This apart-
minutes, and packed in a box a yard square. The ment is lighted from the pavement, and occupies
hind-fork is curved, and may be made springy to the entire space under the Warren-street sidewalk.
distribute the shocks of the roadway, as well as The tunnel starts from the east end of the recep-
lessen their force. The mud-protector fits on a tion-room, and extends on a curve to the centre
square at the top of the front-fork, the foot-rest of Broadway, thence in a straight line down to a
with the foot-drag above that, and the hind-fork point a little beyond Murray-street, where the
over all, protected by a thick india-rubber washer shield, or tunnelling machine, now rests. We
and kept in its place by a screw-the mud-guard present two views of the novel mechanism by
and the foot-rest turning with the wheel. In which the tunnel is bored, one of which shows
level countries the foot-rest will not be needed at the workmen engaged in driving the machine
at all; and no one should use a foot-rest, i.e., go ahead; the other a sectional diagram, showing
down hill, until he has the machine under perfect the details of construction. The shield consists
control. The ordinary leg-rest is a dangerous of a large cylinder, open at both ends, with
feature in the common bicycle. On the new plan shelves arranged within the front end to receive
there is quite sufficient play for guiding the the earth and prevent it from falling too rapidly
wheel round any curve in the road. a is the into the shield; at the rear of the latter, placed
front fork; b guard; e hind fork; d saddle and around its periphery, is a series of powerful
spring; f curved bar supporting foot-rest and hydraulic rams, eighteen in number, all connected
drag; g foot-rest; h projection to press the drag; with a single water-pump. From the rear of the
to fix underneath the foot, the better to grasp the hoop or band of sheet steel, two feet wide, and
i drag. Fig. 7 shows a semicircular metal clip shield, and passing entirely around it, extends a
one-eighth of an inch thick, termed the hood.
The brick tunnel is erected within this hood,
which at all times covers the end of the masonry,

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foot-crank.

Fig. 1 and 2 are a plan-view and a side- THE BROADWAY PNEUMATIC TUNNEL,

drawing of a tricycle of a superior description to carry four-two men sit over the front wheels, a third over the back, and the fourth in a cushioned

seat in the middle; though the single wheelWE give a series of engravings illustrating
the progress and completed appearance of
may be put in front, if preferred, and the middle the pneumatic tunnel now nearly completed in
seat be put looking backwards. Again, a perfect New York.
change of muscular power is provided for, as the
front men work a power and half levers, and the
hind one foot cranks-as in Machine No. 3 and
4. It can be steered from behind, from the
middle seat, or by the front wheels, as the axle
is boxed in the middle. Foot rests are provided
as a fulcrum for the feet, and a back rest as one
for the back, enabling the whole power to be
spent upon the levers. It can be dragged both
from the front and hind wheels. One man on the
hind seat has propelled himself and the machine
carrying another person with the greatest ease.
If the middle seat is removed and the mid-fork
is strengthened so as to do away with an axle, it
is, Dr. Clarke believes, the very lightest and
easiest-worked carriage possible that could be
constructed to carry three persons.

In Figs. 1 and 2 a are the saddles; b middle
seat, cushioned; c inner foot-crank for inside
lever; d foot crank for hind seat; e anterior
forks; f mid-fork fastened to anterior fork; g
small hand-levers to turn the hind-wheel, for
middle man; h the cords for do.; i movable
back-rests; k axle, boxed in the middle; 7 foot
rest for front men; m the drag; n horizontal
projections for toes to press the drag on the
wheel; p hand levers (a power and a half); s
luggage shelf. In Figs. 3 and 4 a are the front
wheels; b hind wheel; c middle fork; d plat-
form on which workers stand; e bent axles to
support platform; f small supplementary wheel way and Warren-street. The portal of the
to prevent, tilting forward; slot or sliding tunnel, as shown in our engraving, is a massive
joint to .engthen or shorten carriage; h cone ornamental structure, of circular form, nine feet

ON THE PHENOMENA OF COMBUSTION.
SPECIAL REPORT.

this subject in the Lecture Room of the Society of Arts, John-
DR. BENJAMIN PAUL, F.C.S., delivered his third lecture on
street, Adelphi, on Monday evening last, to a large audience.

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