to carry the total flow of lines of force at a moderate induction.

It has hitherto been customary to build up the armature core with complete discs of thin wrought iron; but in the. machines made according to the present invention Mr. Kapp

of thin segmental core plates insulated from each other by varnish, paper, or other suitable means, until a certain depth measured parallel with the spindle is reached. There is next threaded upon

cubes of the enamel designed for forming the mosaic of thin hoop wood. In order to put these parts of a special cement. The artist can thus constantly the frame and remove the plaster. All the pieces are placed alongside of each other and imbedded in the design in place, it is only necessary to strip off compare and follow all the shades of his design. fit together like squares of faïence, and may be put Another and more rapid process consists in making in place by means of cement.-Les Inventions a sketch of the subject upon strong paper containing Nouvelles.

ENGLISH MECHANIC AND WORLD OF SCIENCE: No. 1361.

THE AQUARIUM.*

AN you imagine section of a

Clake with its water-reeds and rushes ourish.
pond,
ing, water-snails creeping on the leaves, fishes
gliding among the stems? Then suppose this in-
teresting collection inclosed within glass walls and
placed in your parlour and called a fresh-water
aquarium. It is not for amusement or ornament
only that these parlour lakes are prepared and
stocked, but for instruction also.
living beings can never be known but by their
The nature of
habits, their habits can never be well understood but
by close and continuous observations, and if we
cannot go down to water to observe the fishes,
molluscs, water-plants, &c., we must bring them
up to us in a very similar condition.

fed on the conferva as well as

APRIL 24, 1891.

for dead fish. It is natural that some fish so re-ratus for this purpose. Prof. A. E. Dolbear, in his
cently introduced into strange surroundings will book, describes a megascope, consisting of a

die, and it is very necessary that these bodies box with a large lens in front and an oxyhyd plain
should be removed before putrescence takes place, light within. Mr. Lewis Wright, in his new work
of the living occupants. If a green turbidity of megascope; but notwithstanding all this, the idea
arises on the water, it can be easily remedied by is current that opaque projection is difficult, and
as the water will become putrefied, to the danger on "Optical Projection," shows two or three forms
excluding light from the aquarium for a few days. several persons well known to the writer are so
For the purpose of occasional aeration a drip-glass thoroughly convinced of the magnitude of the
the water may be lifted and allowed to drip slowly project in this way.
may be arranged, by means of which a portion of undertaking that they do not make the attempt to
of gaining a knowledge of nature than by a close
and careful attention to a well-stocked aquarium.
back. There is no better or more interesting way

NEW

ELECTRO - PHOTOTYPY : A
METHOD OF PHOTO-MECHANICAL
PRINTING.*

two or three points are noticed in the beginning.
In describing a few ways of opaque projection
First, all the light attainable is required; second,
all kinds of work cannot be done with one and the
same instrument; and third, to secure the best
effects, suitable shadows are as necessary as strong
large scale with a source of illumination inferior to
lights. It is useless to attempt projection on a
of three insures a much better effect.
the calcium light. For large objects and a large
screen, two large burners are essential, and the use

the burners is determined by the focal length of
(Fig. 1), the lens has a focal length of 24in. The
box is made 4in. longer, i.e., 28in., to allow of
The length of the box inclosing the object and
the object-glass. In the instrument illustrated
image on the screen.
moving the object, for the purpose of focussing the

arranged at one side of the megascope box, at
slightly different elevations, and a short distance
When two oxhydrogen burners are used, they are
are used, the third is placed at the opposite side of
the box. It increases the volume of light and
apart, to secure soft shadows. When three burners
modifies the shadows. If the apertures of the
burners are the same, they may all be supplied with
gas from a single pair of cylinders by using branch
object as possible, without bringing them into the
field of the objective.
pipes. The burners should be pushed as near the

The principle on which aquaria are constructed and maintained consist mainly in balancing animal by vegetable life, thus: If a few fish were confined in a vessel and the water remain unchanged, they would soon droop and die. The water would not sustain life after the fish had deprived it of the WILL not go into the history of the inception oxygen by passing it through their gills in breathing. If, by means of any kind, the water can be process further than to say that it dates from 1881. and development of this photo-mechanical raised and recharged with the vital element, oxygen, production of half-tone process blocks feel conits power of sustaining animal existence is propor- vinced the present methods of obtaining the result I think most scientific men who understand the tionately prolonged. This may be done by a fountain jet. Experiments show that water-plants, method of producing a block from a photograph properly acted upon by light and under other suit- without the conversion into a fatty-ink or bitumen are too roundabout, and that could some direct able conditions, will, instead of taking from, add to image, and subsequent skilled etching, be dis the proportion of oxygen present, and will thus re-covered a great impetus would be given to the store the balance without resorting to mechanical aëration. This explains why tanks used by early solution, I think the present process may claim to experimenters still exist, their tenants living and be on the right track, and that it only needs the graphic arts. Without pretending to a final breeding healthily, and the same water as first put experience gained in everyday work to render it a in still capable of supporting life. A prominent experimenter states that he placed letterpress block process of high quality. The two small gold fish in a glass jar capable of holding process is simply a means of direct electrotypy on twelve gallons of water. Half filling the vessel the electro being then passed on to the printer. with fresh spring water, and placing some sand and Producing a relief on a gelatino-bromide negative a relief, produced on a gelatine-bromide negative, mud at the bottom, with fragments of limestone and dispenses with the use of collodion, with zinc or sandstone, he planted a small Valisneria, a water- other surfaces sensitised with bichromated albumen double-convex lens; but a 7in. or 8in. would be plant, in the mud and left the whole undisturbed. and gelatine or bitumen, and with the difficult art better. The lens is mounted in a soft wood ring, After a time the water became thick, and a coating of etching. I must be understood as distinctly and suspended over a circular aperture in the front of scum or confervoid vegetation obscured the glass referring to half-tone block work. In the present case the objective consists of a 6in. so that the interior could not be discerned. On introducing a few water-snails, he found that they alkaline pyro or hydrokinone, then fixed in strong 28in. by 3in. thick when not in use. Fig. 2 shows A gelatino-bromide negative is developed with is made to fold, so as to occupy a space of 18in. by of the box. For the sake of convenience, the box matter of the plant, and soon restored the water to does not absorb too much water), the plate is placed ordinary box cover, with the exception of the on the decayed hypo; when washed (care being taken the image the construction clearly. The top, f, is like an a clear and healthy condition. The pruning of the on a metal support and gradually heated to 212° central draught hole surrounded by a collar. To older leaves encouraged the growth of many small Fahr. This is very simple, and if tried, will result the bottom, g, are hinged the end, , sides, ij, and shoots. The snails flourished on the vegetable in an extraordinary production, the most probable the front, . The cap, m, is supported over the matter, which they consumed, and the fishes thrived being the shadows of the image running all over opening in the centre of the cover by the wood on the eggs which the snails deposited, and in the the plate. If we take a negative that has been screws inserted in the corners. renovated water. The aquarium is subject to a great many modi- impressed with a screen of some definite pattern, arranged to hang over the large opening in the end fications in shape. The proper proportion of dimen- of the screen image holds an amount of reduced ing for the insertion of the gas tubes. The side sions should be something like this: Length, 24in.; silver, bearing some definite proportion to the piece i is discontinued near the back end of the we get a very different result. The lens n is width, 18in. and depth, 10in. or 12in. A great action of light and development; this is sur-box, to provide an opening for the insertion and Each little dot piece k. In this end piece there is a smaller openmany, and in fact the greater number, are of im- rounded by a fine line, containing no silver, due removal of objects. This opening is covered with a proper form, being as deep or deeper than they are to the opacity of the screen preventing any action. black curtain, which falls over the arm, and prewide. In an aquarium the fact that the propor- If we examine the little squares, we find the vents the escape of light. Upon the inner surface tional surface to the air is of far more importance reduced silver has produced a certain amount of of the back end of the box is secured a piece of than the volume of water contained, should be insolubility, the absorption or combination of the white cardboard for a background. The sectional borne in mind. A sloping bottom is also preferable. freed bromine with the gelatine a further amount, view, Fig. 1, best shows the internal arrangement. The bottom should be laid with sand or small and a similar action due to the pyro. Now, on The object must be inserted in position and moved gravel suited to the condition they are intended to raising the temperature of such a film to the melt-forwards or backwards until it is focussed. If diffi represent. Some water animals like to burrow, ing point of the part holding no silver, these culty is experienced in holding the objects properly and should therefore have a bed of sand in which portions melt, and are drawn by capillary action for exhibition, they may be placed on a movable to gratify their desires in that direction. A few under the unmelted dots. This capillary action is support. bright pebbles added give the vessel a pleasing evidently proportional in some way to the amount appearance and afford shelter for minute animals. of reduced silver, and, therefore to the image. The A few larger stones laid on the gravel is all that is importance of this consists in that the image becomes necessary to give shelter to fish. Ornamentation in the actual regulator of the sizes of the dots; such this case should consist in the water-plants. Clear, being the case, we have the remarkable fact that the river water is preferable, as it is best for both image is engraving itself, and the two operations of animal and vegetable life. Among the plants com- relief and graduation are proceeding at the same mon and easy to get for your aquarium are, "star- time. To understand the nature of this, it is worth, "" "water soldier," "frog bit," and "water plantain." Most of the work, the endeavour is made to produce a graduated "new water weed," smaller species of fish will live and breed freely in necessary to remark that, in ordinary half-tone tanks well supplied with oxygen, and there is no all who have studied the matter-and then reproduce way in which the beauties of their forms and from this graduated screen negative by etching in screen negative by optical means-well-known to markings can be so well seen as through perpen-zinc or copper. The blocks shown are all electros dicular, evenly-moulded glass. Here their graceful, taken direct off camera negatives, the oval block easy movements can be watched without their being direct from a silver print, the others from being distorted by refraction. Most of them enjoy glass positives. The large electro is deposited by their dwelling, if we can judge from their lively dynamo, and may be readily printed by any printer; yet not restless bearing. It must be remembered the other blocks are deposited by battery, and rethat they are mostly animal feeders, and if put into quire fine printing. It remains now to produce a vessel with other animals smaller or weaker than something between-a not very difficult matter at themselves, they will not live quite as happily as the present stage. the cat and mice in the "happy family." fishes are much more voracious than others. I heard of an instance where a pike 2in. long attacked and destroyed a fish of another species half as long OPTICAL PROJECTION OF OPAQUE cosmorama lenses, sold by the principal opticians,

Some

divided. A bunch of California grapes forms a fine object. A bouquet of flowers is beautiful. Shells, especially polished ones, are very pleasing objects. Fruit of all kinds projects well, either whole or Peacock and other feathers show well. and bronzes, plaster casts, toys of various kinds, particularly of the Japanese variety, carvings, embroidery, paintings, engravings, photos, the pages suitable size, and parts of machinery, or apparatus Pottery of a book, are all of interest. Whole machines of a this way. of almost any kind, may be shown to advantage in

without the use of a box is illustrated in Fig. 3. In this case one room serves as a megascope box, and another as the room in which to place the screen. Another way of accomplishing the same result already described is observed. In this case the lens and all escape of light is prevented, excepting, of course, that which passes through the lens. The The same general arrangement as that is secured over the space between two sliding doors, screen is made by translucent tracing paper. lens may be such as is used for the examination of again. The paintings or photographs, but the kind known as Among the many suitable fish for aquarium study, the sunfish, perch, catfish, young bass, trout, means of the optical lantern affords a way of calcium lights are used. The objects may be held are preferable, on account of being about the right and German carp are preferable where they are obHE projection of opaque or solid objects by tained of a diameter of 6in. or 7in. focus. They are not expensive, and may be obtainable. Water tortoises and newts if kept should showing upon the screen a large variety of objects in front of a white or tinted background, or the be supplied with mud, and also some exposed rock in their natural colours, and greatly magnified. background may be omitted. Two or three where they can stay out of the water at their The form of lantern best adapted to this purpose is necessary that no stray light should escape into the snails, and slugs are useful as scavengers. The first projection briefly describe different forms of appa-opaque white screen may be used in this arrangeAmong molluscs, fresh-water mussels, the simplest imaginable. It is absolutely few days your aquarium should be well watched The works on optical room in which the image is thrown. Of course an By HERBERT S. ROBINSON, in Popular Science News,

leisure.

oston, U.S.A.

OBJECTS.+

the Camera Club.
From a Paper by Mr. HENRY SUTTON, in the Journal

of

+ By GEO. M. HOPKINS, in the Scientific American.

ment if desirable.

For the projection of fine objects, such as gems and their settings, a watch movement, or a fine piece of machinery or apparatus, the arrangement

some of the dealers in lanterns.

shown in Fig. 4 is effective. A plan view of the | Apparatus similar to this in principle is sold by
apparatus is here shown. The objective of the
lantern is removed and supported at an angle with
the optical axis as indicated. The lime is pushed
forward so as to cause the divergent cone of light
to cover the object d, as shown. The light reflected
from the object d passes through the objective to
the screen.

The wonder camera shown in Fig. 5 is an instrument having a marvellous amount of power considering the source of light, which is simply a single Argand kerosene burner. The lamp flame is in one focus of the ellipsoidal reflector, and the picture or object to be shown is placed at the other focus, on The wire frame e, secured to the front of the the swinging adjustable holder. Opposite the lantern and held by the stand f, is designed to holder in a perforation in the reflector is placed the support a thick black cloth for shutting in all light objective by which the image is projected on a excepting that passing through the objective. I screen three or four feet distant. The small plan

FIG. 2.

HEED

discharge rate and large capacity less; and efficiency not at all. In spite of this, the results obtained by two of the inventors, Messrs. Bradbury and Stone, were not bad.

Two forms of plate were devised by these geilemen, of which the first is very curious in its coustruction. Each plate consists of a number f elements, and each element is made by bending two

FIG. 3.

L

strips of lead into what most of the children, especially among the Germans, call a Jacob's ladder. (Fig. 1).

of its length, taking care not to allow it to become This is then warmed, and pulled in the direction

By C. W. PIKE, Instructor in Electrical Engineering, University of Pennsylvania. A Paper read before the Franklin Institute.

SCIENTIFIC SOCIETIES.

ROYAL METEOROLOGICAL SOCIETY.
TE
THE usual monthly meeting of this society was
held on Wednesday evening, the 15th inst.,
at the Institution of Civil Engineers, 25, Great
George-street, Westminster, Mr. A. Brewin, Vice-
President, in the chair.
Mr. J. Baxendell, Mr. H. Champ, and Mr. S. H.
Ridge, B.A., F.R.G.S., were elected Fellows of the
Society.

The following papers were read:

1. "Some Remarkable Features in the Winter of 1890-91," by Mr. F. J. Brodie, F.R.Met.Soc. The author points out the peculiarities or special features of interest in the weather which prevailed over the British Isles during the past winter. In addition to the prolonged frost which lasted from the close of November to about January 22nd, he finds that the barometric pressure for the whole winter was about a quarter of an inch above the average, and that when the wind was not absolutely calm there was an undue prevalence of breezes from some cold quarter. The percentage of winds from the southward did not amount to one-half of the average. The number of foggy days in London was no fewer than twice the average. The rainfall over the greater part of the British Isles was less than half the average. The author says that almost every element in the weather has been influenced to an abnormal degree by the remarkable prevalence of high barometrical pressure, and if we were called upon to define the season 1890-91, we should have little hesitation in giving it the name of the "anti cyclonic winter." 2. "The Rainfall of February 1891," by Mr. H. S. Wallis, F.R.Met.Soc. This was one of the driest months on record; the mean rainfall over England, excluding the Lake District, being only 0.066in., or about one-fortieth of the average.

3. "On the Variations of the Rainfall at Cherra Poonjee in the Khasi Hills, Assam," by Mr. H. T. Blanford, F.R.S. Cherra Poonjee has long been notorious as having a heavier rainfall than any other known place on the globe, the mean annual fall being frequently given as about 600in. Mr. Blanford has made a critical examination of the various records of rainfall kept at this place, and is too high, and that the average annual rainfall is probably only a little over 500in.

has come to the conclusion that the above amount

ROYAL MICROSCOPICAL SOCIETY.

HE seventh of held on Tthe rentimeet the version was W., the President, Dr. R. Braithwaite, F.L.S., in the chair. The President said it would no doubt be remembered that, at the last meeting, Mr. T. Charters White exhibited some specimens of sections of teeth permeated with collodion. He had now presented three slides to the cabinet of the society, which would be valuable as illustrations of the results obtained by the process which he described in his paper.

Prof. Bell, in reply to the President, said he had not yet read the book on "Protoplasm and Life," presented by Mr. C. F. Cox; but he had-as he often did-opened it at the end, where his eye fell upon the words, "Here I must leave the subject, lame and impotent though the conclusion may be." He would take it home, and see if he could get something better out of it than that.

Mr. J. Mayall, jun., said there was also amongst the donations a copy of the Report and Proceedings of the Ealing Microscopical Society, which was worthy of notice, as it was not often that a society of so little pretension issued such an interesting abstract of its proceedings. Amongst other papers in the report, there was one by Mr. Seebohm which had greatly interested him, and there were some others which he thought would also be found very well worth reading.

The President read a letter from Mr. J. Aitkin, of Falkirk, dated from Mentone, on "A Spot Mirror Method of Illumination."

Mr. Mayall said the application of an opaque oft to block out more or less of the central portion of the mirror had long been known. In some of the microscopes made in the last century by Dellebarre, the optician of Delft, Holland, there was a strip of brass 3in. or 4in. in length, with disc like ends of different sizes, blackened or covered with cloth, made to slide under the stage in a springclip, and thus exclude the central light from the mirror, and give a more or less dark ground. Other methods had also been adopted by Dellebarre, one of which was to cement discs of black paper of different sizes on the under-faces of glass stageplates. Central stops were very commonly applied to a disc of diaphragms rotating beneath the stage. The more modern arrangements of central stops to be used in conjunction with some form of condenser, or with a Lieberkühn, were far preferable. Prof. Bell read an abstract of a paper contributed by Surgeon V. Gunson Thorpe, R.N., on "Some New and Foreign Rotifera" found on the West Coast of Africa, and belonging to the genera Trochosphera

and Floscularia. The paper had been submitted to
their late president, Dr. Hudson, who regarded it
as one of great interest, and strongly recommended
the society to print it in extenso with the figures.
Mr. E. M. Nelson, referring to the subject of his
paper read at the meeting of the society in March
last, exhibited two forms of bull's-eye condenser,
and the other was a new and simpler form than he
one of which was made] like Herschel's aplanatic,
had previously described, being made of two plano-
peculiar, and what he considered to be the most
convex lenses, the mounting of which was also
useful method. This condenser seemed to answer
aberration being only about one-fifth of that which
its purpose admirably, the amount of spherical
existed in the old form.

Notes on Diatom Structures as Test Objects,"
Mr. Nelson also read a paper entitled "Further
which he illustrated by photographs.

beautifully clear, and would, he thought, be found
The President said the photographs appeared
of much interest as bearing upon the points to
which Mr. Nelson had particularly drawn their

attention.

the Treatment of Diatoms by Chemical Deposi-
Mr. C. Haughton Gill's "Additional Note on
tions" was read, the subject being illustrated by
photo-micrographs.

were of great interest; but the subject was so new
The President thought Mr. Gill's experiments
that discussion could hardly take place, especially
in the absence of the author, which he regretted to
learn was due to illness.

the stage, instead of being screwed on to the front of the limb, as is usually done, is made in a solid casting taking the substage beneath, and going right into the joint at the top of the pillar. The limb is fitted into the stage bracket at the pillar joint, held firmly by screws, and the joint bolt of the pillar goes through the whole-limb and stage firm as though they consisted of one piece of metal bracket-rendering the limb, stage, and substage as throughout. The mechanical stage is of large size, is a sliding bar to carry the object, and which can and gives lin. of motion each way. In the centre be fixed central by means of a screw, or can be covering the whole surface of the stage, for rough entirely removed and replaced by another plate work, to save damage. The foot is of the horseshoe shape, with cork pads at the points of contact with the table. The aim has been to turn out an instrument rigid in construction and convenient in work at a moderate price. They also exhibited a design, and with every facility for highest class new achromatic condenser of 10 N.A., mounted with iris diaphragm, specially suitable for photographic purposes.

Minot's microtome, made by Zimmermann, of
Mr. C. Lees Curties exhibited a new form of
Leipsic, for cutting serial sections.

Mr. Greenfell

Mr. George Western gave a description with known rotifers. black-board illustrations of some new or littlespots, he thought was most probably a species of One species, possessing no eyePleurotrocha. A second was a tubeless Ecistes, possibly Ecistes mucicolus, hitherto unnoticed in endeavoured to solve was as to the existence or not of Limnoides myriophylli, somewhat Mr. Mayall said the problem Mr. Gill had Britain. The third form described was, he thought, cellular structure in diatoms extending through Limnias cornuella, discovered and described by Mr. resembling their substance, and this he sought to demonstrate Rousselet in a former number of the Club's Journal, by making chemical depositions of a more or less but having no rings to its tube. opaque character, which would probably fill up the described and figured some cavities sufficiently to be plainly distinguished by peculiar organisms found at the last excursion in the microscope. He (Mr. Mayall) had some time the grounds of the Botanical Gardens, Regent's ceedings of the Belgian Microscopical Society, on a Heliozoa, but which might possibly require a new ago translated a paper which appeared in the Pro-Park, which he was inclined to ascribe to the process of preparing sections of diatoms by grinding genus, or even family, to receive them. portions of cementstein from Jutland. The sections ject gave rise to a discussion as to the nature of obtained in this way were imbedded in the material these peculiar forms, one of which had a superforming the matrix of the stone and were filled up ficial resemblance to a diatom, but the pseudopodial points which Mr. Gill had reached in another way. which, in Mr. Greenfell's opinion, was evidence of by the same material, showing to some extent the processes stained with Kleinenberg's hæmatoxylin, He thought that Mr. Gill's observations were of still its being animal and not vegetable. The usual greater interest because he had not merely taken a announcements were then made, and the pronatural formation, but had deliberately experi- ceedings terminated. The next meeting will be mented with the definite purpose of testing a special on Friday, May 15th. point, thus applying to microscopy what Herschel would have termed an 66 'experiment of inquiry'

REFERRING Elaterite

The sub

hitherto been regarded as almost beyond the sphere W. Robinsong to interito found in Ross-shira Mar
a questioning of on a point that
of experiment. Dr. Flögel's sections of diatoms is an intensely black, lustrous, sticky substance
made with his unique microtome dealt with the found in fissures in the conglomerate above the red
same point by direct experiment, but unfortunately sandstone at the Craig Well, near Dingwall. On
the production of such sections was attended by dry distillation, it yields an inflammable oil, gas,
very great difficulties, and their preservation for and water. It melts at 140deg., leaving on ignition
inspection by other observers was apparently so a slight ash containing ferric oxide and lime. Quite
uncertain as to be unreliable, judging from the similar mineral tar is found near Castleton in fissures
specimens sent by Dr. Flögel to the Society. Mr. in the Derbyshire mountain limestones.
Mayall regretted that Mr. Gill's photographs
of the specimens he described were so faint that it
would not be possible to utilise them for any photo-
mechanical process of printing for the Journal.
Mr. Mayall said that in Part IV. Vol. I. of the
Journal of the Liverpool Microscopical Society there
was a paper by Mr. T. Comber, in which he dealt
very practically with the processes of photo-
micrography with sunlight. He was, of course,
sorry that this paper did not come directly to the
R. Micr. Society; but considering the interest which
attached to the subject, and the references made
recently to Mr. Comber's work, the paper would
probably be dealt with rather extensively in the next
number of the Journal.

The President asked the Fellows present to bear in mind that the conversazione was fixed for Thursday, the 30th of April, at which he hoped to see a good attendance, and that the next ordinary meeting would take place on the 20th of May.

QUEKETT MICROSCOPICAL CLUB. THE 292nd ordinary meeting of this club was held on Friday, April 17th, at 20, Hanoversquare, W., Dr. W. H. Dallinger, F.R.S., &c., president, in the chair.

phenomenon of frequent occurrence at Ben Nevis "SILVER THAW" is the name applied to a winter observatory. It consists of rain falling when the air is below freezing point, and congealing whento an inversion of the temperature, which is lower ever it reaches the ground. Of course, this points on the mountain top than at greater heights, and, being largely associated with a cyclonic distribu tion of pressure, it is of considerable "forecasting

value.

The Tallow-Tree in China.-Mr. Hosie, the British Consul at Wenchow, in his last report describes a curious vegetable product which is culti

vated in his district. This is the tallow tree (Stillingia sebifera, Roxb.), the root of which produces oil as well as tallow. The berries, which resemble coffee-beans in appearance and size, are first steamed and then pounded in an ordinary ricetrough. By pounding, the soft mealy mesocarp is partially separated from the kernels. The whole is are just large enough to allow the mealy matter to then placed in a bamboo sieve, the meshes of which be scrubbed through, and small enough to keep back the kernels, which are ihard, black, and about the size of peas. From the mealy matter the tallow is expressed in primitive wooden presses. To obtain The minutes of the preceding meeting were read oil the kernels are dried and passed between two and confirmed. Eleven candidates were balloted millstones, held at such a distance apart by means for and duly elected members of the club. The of a bamboo pivot as to crush the hard shells of the additions to the library since the last meeting were kernels without injuring the white interiors. The announced. Messrs. Watson and Sons, of 313, whole is then passed through a winnower, which High Holborn, exhibited and described a new form separates the broken shells from the solid matter. of microscope, made by them to the specification of The latter is then placed in a deep iron pan and Dr. Van Heurck, of Antwerp, for photography and roasted until it begins to assume a brownish colour, high power work. A special feature of it is the man- the process being accompanied by continual stirring ner in which the fine adjustment is fitted to the sub-to prevent burning. The crushed shells make an stage. The movement is effected by means of a excellent fuel for the purpose. It is then ground by lever, which works by a screw from the upper sur- a huge stone roller in a circular stone well, steamed, face of the stage, so that the fine adjustments for both the body and substage can be worked simultaneously. The construction of the instrument is also unusual. Each part fits into another, and is not merely screwed to it; thus the bracket carrying

made into circular cakes with bamboo and straw casings, and passed through the wooden press. A good lighting oil of a brownish-yellow colour is thus obtained. The tallow is called "p'i yu"-that is, skin, or external, oil.