Chapter XV: TECHNOLOGY.--A New Process for the Bleaching of Jute.--By (3)

We cannot view the extent of change in the organic life induced by the low wave of heat without seeing at once the sweep of mischief which exposure to the wave may effect. It exerts an influence on healthy life in the middle-aged man, and I know of no disease which it does not influence disastrously. Is the healthy man exhausted, it favors internal congestion; has he a weak point in the vascular system of his brain, it renders that point liable to pressure and rupture, with apoplexy as the sequence; is he suffering from bronchial disease, and obstruction, already, in his air passages, here is a means by which the evils are doubled; has he a feeble, worn-out heart, it is unable to bear the pressure that is put upon it; has he partial obstruction of the kidney circulation, he is threatened with complete obstruction; is he indifferently fed, he is weakened generally. It is from this extent of action that the mortality of all diseases runs up so fast when the low wave of heat rolls over the population, affecting, as we have seen, the feeblest first.

Another danger sometimes follows which is remote, but may be fatal, even to persons who are in health. It is one of the best known facts in science that when a part of the surface of the body has been exposed long to cold, the greatest risk is run in trying suddenly to warm it. The vessels become rapidly dilated, their coats relax, and extreme congestion follows. But what is true of the skin is true equally, and with more practical force, of the lungs. A man, a little below par, goes out when the wave of temperature is low, and feels oppressed, cold, weak, and miserable; the circulation through his lungs has been suppressed, and he is not duly oxidizing; he returns to a warm place, he rushes to the fire, breathes eagerly and long the heated air, and adds to the warmth by taking perchance a cup of stimulant; then he goes to bed and wakes in a few hours with what is called pneumonia, or with bronchitis, or with both diseases. What has happened? The simple physical fact of reaction under too sudden an exposure to heat after exposure to cold. The capillaries of the lungs have become engorged, and the circulation static, so that there must be reaction of heat, inflammation, before recovery can occur. Nearly all bronchial affections are induced in this manner, not always nor necessarily in the acute form, but more frequently by slow degrees, by repetition and repetition of the evil. Colds are often taken in this same way, from the exposed mucous surfaces of the nose and throat being subjected first to a chill, then to heat.

The wave of low temperature affecting a mixed population finds inevitably a certain number of persons of all ages and conditions on whom to exert its power. It catches them too often when they least expect it. An aged man, with sluggish heart, goes to bed and reclines to sleep in a temperature, say, of 50 deg. or 55 deg.. In his sleep, were it quite uninfluenced from without, his heart and his breathing would naturally decline. Gradually, as the night advances, the low wave of heat steals over the sleeper, and the air he was breathing at 55 deg. falls and falls to 40 deg., or it may be to 35 deg. or 30 deg.. What may naturally follow less than a deeper sleep? Is it not natural that the sleep so profound shall stop the laboring heart? Certainly. The great narcotic never travels without fastening on some victims in this wise, removing them, imperceptibly to themselves, into sleep ending in absolute death.

SOME SIMPLE RULES.

The study of the physiological influence of the wave of low temperature, and of its relation to the wave of mortality, suggests a few rules, simple, and easily remembered.

1. Clothing is the first thing to attend to. To have the body, during variable weather, such as now obtains, well enveloped from head to foot in non-conducting substance is essential. Who neglects this precaution is guilty of a grievous error, and who helps the poor to clothe effectively does more for them than can readily be conceived without careful attention to the subject we have discussed.

2. In sitting-rooms and in bedrooms it is equally essential to maintain an equable temperature; a fire in a bedroom is of first value at this season. The fire sustains the external warmth, encourages ventilation, and gives health not less than comfort.

3. In going from a warm into a cold atmosphere, in breasting the wave of low temperature, no one can harm by starting forth thoroughly warm. But in returning from the cold into the warm the act should always be accomplished gradually. This important rule may readily be carried in mind by connecting it with the fact that the only safe mode of curing a frozen part is to rub it with ice, so as to restore the temperature slowly.

4. The wave of low temperature requires to be met by good, nutritious, warm food. Heat-forming foods, such as bread, sugar, butter, oatmeal porridge, and potatoes, are of special use now. It would be against science and instinct alike to omit such foods when the body requires heat.

5. It is an entire mistake to suppose that the wave of cold is neutralized in any sense by the use of alcoholics. When a glass of hot brandy and water warms the cold man, the credit belongs to the hot water, and any discredit that may follow to the brandy. So far from alcohol checking the cold in action, it goes with it, and therewith aids in arresting the motion of the heart in the living animal, because it reduces oxidation.

6. Excessive exercise of the body, and overwork either of body or of mind, should be avoided, especially during those seasons when a sudden fall of temperature is of frequent occurrence. For exhaustion, whether physical or mental, means loss of motion in the organism; and loss of motion is the same as loss of heat.

One further consideration, suggested by the subject of this paper, has reference to the bearing of the public toward the labors of the medical man in meeting the effects of the low wave of heat. The public, looking on the doctor as a sort of mystical high priest who ought to save, may often be dissatisfied with his work. Let the dissatisfied think of what is meant by saving when there is a sudden fall in the thermometer. Let them recall that it is not bronchitis as a cause of death, nor apoplexy, nor heart disease, as such, that the doctor is called on to meet; but an all-pervading influence which overwhelms like the sea, and against which, in the mass, individual effort stands paralyzed and helpless. When the doctor is summoned the mischief has at least commenced, and, it may be, is so far over that treatment by mere medicines sinks into secondary significance. Then he, true minister of health, candid enough to bow humbly before the great and inevitable truth, and professing no specific cure by nostrum or symbol, can only try to avert further danger by teaching elementary principles, and by making the unlearned the participators in his own learning.--_The Asclepiad._

* * * * *

THE TREATMENT OF GLAUCOMA.

As this disease is so fatal to vision, any remedy that may be suggested to diminish the frequency of its termination in blindness cannot fail to be read of with interest. M. Nicati, in the _Revue generate de clinique et de therapeutique_, has had marked success in the treatment of glaucoma by drainage of the posterior chamber, either by sclerotomy or by sclero-iritomy, as the conditions of the individual case may require.--_N.Y. Med. Jour._

* * * * *

A TWIN SCREW LAUNCH RUN BY A COMPOUND ENGINE.

The launch shown in our illustration was built in New Westminster, British Columbia, Canada. She is 42 ft. keel and 7 ft. beam, and has 4 ft. depth of hold. She has an improved Clarke compound engine, also shown in an accompanying illustration, with a high pressure piston four inches in diameter, and a low pressure piston eight inches in diameter, the stroke being six inches, and the engine driving two twenty-six inch screws. With 130 pounds of steam, and making 275 revolutions per minute, the launch attains a speed of nine miles per hour, thus fully demonstrating the adaptability of this engine to the successful working of twin screws.

In the Clarke engine, the exhaust pipe from the high pressure cylinder leads to the steam chest of the low pressure cylinder, while the piston in the upper cylinder is secured on a piston rod extending downward and connected with a piston operating in the lower cylinder, the exhaust pipe from the latter leading to the outside. On the piston rod common to both cylinders is secured a crosshead pivotally connected by two pitmen with opposite crank arms on crank shafts mounted to turn in suitable bearings on the base, which also supports a frame carrying the low pressure cylinder, on top of which is a frame supporting the high pressure cylinder. The valves in the two steam chests are connected with each other by a valve rod connected at its lower end in the usual manner with the reversing link, operated from eccentrics secured on one of the crank shafts.

The crank arms stand at angles to each other, so that the crank shafts are turned in opposite directions, and the position of the link is such that it can be readily changed by the reversing lever to simultaneously reverse the motion of the crank shafts. On the crank shafts are also formed two other crank arms pivotally connected by opposite pitmen with a slide mounted in vertical guideways, supported on a frame erected on the base, the motion of the crank shafts causing the vertical sliding motion of the slide traveling loosely in the guideways, and thus serving as a governor, as, in case one of the propellers becomes disabled, the power of the shaft carrying the disabled propeller is directly transferred to the other shaft through the crank arms, pitmen, and slide, and the other propeller is caused to do all the work. All the parts of the engine are within easy reach of the engineer, and there are so few working parts in motion that the friction is reduced to a minimum.

It is said that the plan of construction and the operation of this engine have been carefully observed by practical engineers, and that, considering the dimensions of the boat, her speed, the smallness of the power, the ease with which she passes the centers, the absence of vibration while running, and the very few working parts in motion, the engine is a notable success. She can be run at a very high velocity without injury or risk, and is designed to be very economical in cost and in weight and space. This engine has been recently patented in the United States and foreign countries by Mr. James A. Clarke, of New Westminster.

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IMPROVEMENTS IN THE CONSTRUCTION OF RIVER AND CANAL BARGES.

By M. RITTER (KNIGHT) VON SZABEL, late Austrian Naval Officer, of Vienna.

This innovation consists essentially in an arrangement by which two distinct vessels, on being revolved round their longitudinal axis to an angle of 90 deg., can be combined into one single duplex vessel, or, to put it in different words, a larger vessel is arranged so that it can be parted into two halves (called "semi-barges"), which can be used and navigated with equal facility as two distinct vessels, as if combined into one. By the combination of the two semi-barges into one duplex barge the draught of the vessel is nearly doubled, the ratio existing between the draught of a loaded semi-vessel and the equally loaded duplex vessels being 5:8 (up to 8.5)

The advantage of the invention consists:

1. In this difference of draught.

2. In the smaller width of the semi-vessel as compared with
the duplex vessel.

3. In the fact that the combination and separation of the
vessels can be effected, without the least disturbance of the
cargo, in a minimum of time.

It facilitates the utilization, to the highest possible extent, of the varying conditions and dimensions of canal locks and rivers.

The transition from rivers to canals, and from larger canals to smaller ones, is expedited by the possibility afforded of, on the arrival at the locks, dividing the vessel in a space of a few minutes; of passing with the semi-vessel, singly, the various smaller locks or the shallow canal, after which the two sections may be re-combined and navigated again as one vessel. The process of "folding up" the two vessels will of course take longer than that of separation.

On rivers, the channels of which are interrupted by sand banks and rapids, the same operation may be carried out, thus avoiding the expense and delay necessitated by, perhaps, repeated "lightering," i.e., reduction of the cargo.

Thus, the through traffic on large rivers like the Danube, with its repeated obstacles to navigation, such as the "iron gate," and several sand-banks known and dreaded by bargemen, would be materially facilitated, any necessity for unloading part of the cargo being obviated; moreover, such a duplex vessel composed of two semi-vessels affords the advantage of utilizing to a fuller degree the power of traction, and one large vessel will be more convenient for traffic than two smaller ones.

Further, the mode of construction of the semi-vessels--both ends of which are of a similar pattern--allows of their being navigated up and down a water channel without the necessity of turning them round; provision having also been made for the fixing of the rudder at either end, which would therefore merely require exchanging. This is of some advantage in narrow river beds and canals, and applies equally to the duplex vessel as to the single semi-vessels.

Each semi-barge on its part is also constructed of two equal halves--which are, however, inseparable--and as there is no distinct stem or stern, any one of these semi-vessels will fit any other semi-vessels of the same dimensions, and can be attached to the same by means of the coupling apparatus, and the two "folded up" into one duplex vessel. This process does not present any material difficulties. The two single boats on being coupled together can be made to lean over toward each other, by filling their lateral water compartments, to such an extent that the further closing up can be easily effected by means of specially constructed windlasses. In the case of petroleum vessels the "folding up" operation is facilitated by the circumstance that the petroleum may be made to serve the purposes of water ballast.

As regards the size and tonnage of the new vessels, this will of course depend on the local condition of the rivers and canals to be navigated. Thus a vessel destined for traffic on canals with locks of varying dimensions will have to be adapted to the dimensions of the smallest existing lock.

Supposing the size of the latter to be such as found in the case of the Rhine-Marne or the Rhine-Rhone Canal, or on the Neckar down to Cannstadt, or in the Danube-Main Canal and some smaller canals in the Weser district, etc., viz.:

Length of lock 34.5 meters.
Width 5.2 "
Depth 1.6 to 2.0 meters.

The semi-barge may be made 32 meters in length, 4 meters in breadth and 2.5 meters total depth, and with a draught of 1.5 meters will be capable of carrying a load of 100 tons (of 1,000 kilos each). Correspondingly the duplex vessel will be able to carry 200 tons, with a minimum draught of 2.4 meters and a width of 5.4 meters, but, with a favorable height of the water level, the draught of the semi-barge may be increased to 1.65 and that of duplex vessels to 2.7 meters.

Where not limited to certain proportions by the dimensions of the locks to be passed, the vessel may in the first place be made longer; the width and height may also be increased accordingly (provided that the proportion of breadth to width is kept within the ratio 4:2.5), so that the semi-barges may be constructed for a single burden up to 300 tons, or 600 for the duplex vessel.

As regards the nature of the cargo, parcels would not be admissible in this instance, but any kind of homogeneous cargo would be suitable which would bear laying over on one side.

Thus this style of vessel would be well adapted for petroleum tank vessels, for the transport of all kinds of cereals, flour, coffee, and sugar in sacks--these latter being held in position by an arrangement of planking and boards so as to prevent any overturning of the goods on the vessels being folded up or taken apart. Similarly in the case of a cargo of loose grain or other loose produce, the same must be prevented from being upset by a kind of wooden casing.

Two semi-vessels loaded with different cargoes may be coupled together, provided that there is not too much difference between their respective draughts. Slight differences may be balanced by the water compartments being filled to a greater or smaller extent.

The peculiar position of the hatches allows of loading the semi-vessels separately as well as when coupled together.

If there is for the time being no necessity for using the vessels in their capacity of separate and duplex barges, any kind of cargo might be loaded that does not require large hatches.

The vessels, on account of their more complicated construction, will be somewhat more expensive, but wherever the advantage offered by them outweighs the extra expenditure, they can be used with success.

The innovation might be of particular importance where a new canal system is being constructed, since the latter might be subdivided into main canals and branch canals--similarly as in the case of ordinary and narrow gauge railways--the main canal being built of a larger section and with larger locks to suit the duplex barges, while the branch canals could be planned of smaller dimensions calculated to suit the semi-barge. Thus the first cost of such a canal system would be materially reduced as compared with a canal installation of one uniform section throughout.

Likewise in mountainous districts with rock soil it would be an important consideration whether a canal had to be blasted out of the solid rock or a tunnel cut, in dimensions suitable for a vessel of 6 or of 14 square meters section below the water line.

In this case, even in certain portions of a main canal--where rendered desirable by the rocky nature of the ground--a smaller section might be adopted, which would only be large enough for single semi-barges, so that the duplex vessel would in these instances have to be taken apart in the same way as in a branch canal.

The saving to be effected by constructing a canal on this principle, as compared with a canal of one uniform section throughout, must be considerable, and the advantages of the arrangement are apparent.

The appended figures will further illustrate the arrangement. Fig. 1 shows two separate semi-barges ready to pursue their journey independently. Fig. 2 shows two semi-barges coupled together ready to be "folded up" by means of ropes and specially constructed windlasses--their lateral water compartments having previously been filled. Fig. 3 shows the duplex vessel after the "folding up" operation just described; and Figs. 4 and 5 show the cross section of two loaded semi-barges as outlined in Figs. 2 and 3.

These Figs. 4 and 5 will also serve to illustrate the manner in which sacks and loose produce should be loaded. Fig. 4 also shows the filled water compartments, and the effect of their weight in making the boats lean toward each other.

The materials most suited for this new style of vessel will be iron and steel such as generally used in the construction of canal and river vessels.

The new ship can be moved by any motor or driving implement, nor could there technically a great difficulty be found for making the boilers move on a quadrant-like rail base in the shape of a circle segment's quarter, or for building a double screw steamer by combining two single screw propellers.

May be a ship owner is willing to submit the innovations to an attempt, so much the more as there is running no great risk by doing so; for in case the ships should not answer the expectations, both separable as well as joinable, they can be used like single ships, without any further alteration being made, except as to the loading gaps.

The above invention is covered by United States patent No. 435,107. Any further information may be had by addressing M. v. Szabel, ix Bezirk, Beethovengasse 10, Wien, Austria.

* * * * *

WELDON'S RANGE FINDER.

Colonel Weldon has recently considerably modified and improved his ingenious range finder, and we illustrate herewith from _Engineering_ the form in which it is now manufactured. It consists of a metal box, the lid of which is shown open in the engraving, and on this lid are fitted three prisms which are the essential constituents of the instrument. When the lid is closed, these, with the compass and level, also attached to the lid, lie inside the metal box, and are thus thoroughly protected. The upper prism marked 1 is a right-angled one and is mounted with the right angle outward; looking into the left-hand corner of this prism one will see in it, by double reflection, objects lying on one's right hand. Below this is a second prism with a principal angle of 88 deg. 51 min. 15 sec., and below this a third with a principal angle of 74 deg. 53 min. 15 sec.

A level and a compass are also mounted on the lid as shown. To use the instrument the observer stands so that the object the range of which is required lies on his right hand, and looking into the left-hand corner of the upper prism views it there by double reflection from the internal faces of the prism. At the same time looking through the opening shown in the lid below the prism he selects some object, which appears nearly in line with the image seen in the prism. He then shifts his position till these two images coincide, in which case lines joining him with the two objects will make right angles with each other. In Fig. 2, O is the object whose range is required, D the object seen by direct vision, and A the position of the observer. The observer now marks his position on the ground, and shifting the instrument looks into the left-hand corner of the second prism, when he again sees the image of the object, whose range is required, by double reflection, but lying now to the right of the object, D. He then retires, keeping in line with A and D, till he reaches B, when the two images again coincide; the lines joining them and the observer now make an angle of 88 deg. 51 min. 15 sec. Then in the triangle, OBA, OA = tan 88 deg. 51 min. 15 sec. X A B = 50 AB. The length AB is easily paced, and the distance OA is 50 times this length.

A longer base, and probably greater accuracy, can be obtained by using the second prism only, as indicated in Fig. 3, in which case the distance of the object is 25 times the distance BC. This second prism is, however, best adapted for predicting the range of moving objects. Three observers are required. Two of them have finders, while the other measures the distance between the two. The first two observers separate, and No. 2 takes a position such that the object is reflected to one side of observer No. 1, whom he views by direct vision. As the object continues to move, its image gets nearer and nearer No. 1, who during the whole of the time moves a little to one side or the other, so as to keep the image of the object constantly in line with No. 2. Just as the image of the object gets very near No. 1, No. 2 calls out "Ready," the distance between the two observers is taken by the third, and when the image of the object actually falls on No. 1 its distance is just 25 times the distance between them, and the guns set to this range are fired by word of command from No. 2.

By using the third prism in conjunction with the second a still longer base of one-fourth the distance of the object can be employed. The range finder can also be used as a depleidoscope for transit observations. For this purpose it is mounted on a block of wood by means of elastic band and leveled by the level on its lid, being at the same time set in the meridian of the place. The lid is opened to make an angle with the horizon equal to the latitude of the place of observation. On looking into the upper prism two images of the sun will be seen on each side of the apex of the prism, which gradually approach each other as the sun nears the meridian, and finally coincide as it passes it, the time of which being noted gives the longitude of the place.

Extensive trials of the instrument have been made both in this country and in India, which agree in showing that the average error in using the instrument is about 21/2 to 31/2 per cent.

* * * * *

WHEELS LINKED WITH A BELL CRANK.

There are four ways in which a connecting rod is made use of in machine work. The first is in linking two wheels together that stand in the same position, but a slight distance off centers. The rod in this case has only to lead the driven wheel around by connecting it with the driver, and consequently has only to endure a pulling strain in the direction of its length. The second is when the rod is called upon to stand a pull and a push at every revolution. The third takes in the matter of the twisting strain that a rod can manage; but the fourth brings the hardest usage that a connecting rod can be called upon to endure, and that is by making a lever of the rod to get a driving action by prying on a fulcrum in the center. In Fig. 1 is seen a case of this kind taken from a machine in which a disk engine was made use of. The rod has a chance to turn about on its center from a ball and socket joint, and engages with both wheels in nicely fitted journals, and boxes set in line with the center of the socket joint, so that when one wheel turns, the rod pries the other around by using the rod as a lever and the ball joint for a fulcrum, giving a uniform leverage all the while, with no dead centers.

To set this arrangement around at right angles, or where the shafts will bring the wheels together, as for bevel gears, a bent lever arm would need to be used, as shown in Fig. 2, but the bend in the connecting arms brings in another feature that must be provided, as it allows the wheels to turn either with or against each other, and leaves two places where the bent arms will come to a dead center. What is needed here is another element that will take all the twisting strain on the rod and keep the pitch of both arms alike in every portion of a revolution. To do this the ball and socket joint will need to be replaced by a gambrel joint like a ship's compass, and arranging the bent driving arms as shown in Fig. 3; then the driving end of the connecting frame will move about in a true circle, producing as great a tendency to turn the driving wheel in one position as another. In this arrangement there must be at least six nicely fitted journals and their bearings, four of which will be required to take care of the forked connecting rod that joins the wheels together. Besides all this the bearings must all line up with the same center that the shafts are centered from or there will be a "pinch" somewhere in the system. It may seem at first that there must be more or less end-on movement provided for, and that the bearings should be spherical; but that it is not the case will be noticed when all the points are understood to be working from one center similar to that provided for in bevel gears.--_Boston Journal of Commerce._

* * * * *

THE DECORATIVE TREATMENT OF NATURAL FOLIAGE.[1]

[Footnote 1: Lectures before the Society of Arts, London, 1891.]

By HUGH STANNUS.

_Lecture I._

Sec. 1.--THE ELEMENTS OF DECORATION.

The chief impelling Motives which have caused that treatment of objects which is now termed _Decorative_, have been:

(a) That necessitated by the Usage, which is FUNCTIONAL;

(b) That resulting from the Instinct to please the eye, which
is AESTHETIC;

(c) That arising from the Desire to record or to teach, which
is the DIDACTIC motive;

The AESTHETIC instinct of the early peoples was gratified by:

(a) The _forms_ of their weapons or tools;

(b) The _patterns_ with which they are decorated;

(c) The _imitation_ of the surrounding animals, e.g. the Deer
scratched on the horn at the British Museum.

Imitation was afterward applied to the vegetable creation; and much of what is termed Ornament was derived from that class of elements.

The ELEMENTS OF DECORATION are the material used by the Artist. They might be considered to include everything that is visible; but since Decoration is a result of the aesthetic instinct, the field is narrowed to such as are pleasing _at the first glance_. And the selection is further limited to such as are suitable to the shape and size of objects.

They may be classified according to their relative Dignity, as follows:

The Human form,
Animal forms,
Natural foliage,
Artificial objects,
Artificial foliage, and
Geometrical figures.

Sec. 2.--THE TWO KINDS OF FOLIAGE.

A Distinction is made between natural and artificial foliage. They have much in common; and consequently many have supposed that our Western artificial foliage is merely a very-much-conventionalized version of natural foliage. The supposition is correct with regard to Eastern Pattern work, but not in Western Architectural ornamentation.

A simple generalization may make this clear. The ordinary stock foliage of the Ornamentist was evolved in connection with:

(In the West) (In the East)
ARCHITECTURE, TEXTILES,
as in Greece. as in Persia.

Hence the primary Elements of decoration were derived from:

(In the West) (In the East)
GEOMETRICAL LINES, NATURAL FLOWERS and LEAVES,
e.g. the meander, spiral, etc. e.g. the pine, pomegranate, etc.

Further, it may be observed that the Method of treating these Elements has been different:

(In the West) (In the East)
The Geometrical lines The natural foliage was
were enriched by the introduction codified by the introduction
of the details of of Geometrical arrangement;
Natural vegetation; thus thus becoming
becoming gradually more gradually more
_naturalesque_. _artificial_.

An APPROXIMATION between the two treatments, sometimes appears; but the two kinds--Artificial, and Natural--are essentially different in origin; and should be kept distinct in their application.

This approximation may be shown, in a tabular arrangement, thus:

GEOMETRY...........................................................NATURE

The patterns are merely The plants are copied as straight lines, dots, and accurately as possible. portions of circles.

The lines become stems. The plant is applied
without repetition.

Leaves are added to the Repetition is used with the
stems. plants.

Serration is added to the Weaving economy induces
leaf-edge. symmetry.

Similarity of serrated Symmetry induces Geometrical
leaf-edge to the Akanthos Severity, and the Omission
plant, is observed; of all details of the
Imitation becomes more original plant which are not
direct; and this artificial easily worked in connection
foliage becomes termed with geometrical
"Acanthus." arrangement.

Flowers generally circular The Flowers and Leaves
in mass-shape, are added (_only_) survive; the growth
at the ends of the spiral of the stems is forgotten;
stems. and tradition does the rest.

Sec. 3.--APPLICATION OF THE TWO KINDS.

Each of these two kinds of foliage has its own proper use. Artificial foliage is appropriate to the enrichment of Architecture; and Natural foliage to those objects which are not architectural, but are termed "movables," including under this term, Furniture, and more especially Hangings and other applications of the Textile art.

This may be seen on comparing the two columns below, of which the L.H. one refers to Architecture, and the R.H. one to Natural foliage.

(Architecture) (Natural foliage)
RULES:
Governed by severe Exhibits _apparent_ playful
rules of Repetition, Freedom. There _are_
Axiality, Symmetry, etc., underlying Rules, which
which are apparent to are detected by the scientific
the passer-by. Hence Botanist; but these
Artificial foliage, being are not seen by the casual
regular in its structure, observer.
is more appropriate than
the (apparently) irregular
growth of Natural
foliage.
CHARACTERISTICS:
Rigidity and Stability. Elasticity and Tremulousness
in every breeze.

LINES OF COMPOSITION:
Geometrical lines. In determinate curves,
The geometrical lines which are very subtile,
and spirals of Artificial and varied, and therefore
foliage demand an unmoving suitable to a hanging and
surface for proper view. swaying material.

The curves of Nature
They would generally be spoiled are not spoiled when on a
if not on a plane surface. folded material.

DISTRIBUTION:
Symmetrical. The Balanced. The growth
symmetry of artificial of natural foliage is generally
foliage is appropriate to symmetrical; but
that of Architecture. this is not apparent.

BEAUTY:
Depends on _form_, with More appropriate to objects
color as a secondary adjunct. which depend on _color_ for
their principal charm.

There have been waves of the desire to introduce Natural foliage into Architecture (e.g. in the "Decorated period" of Gothic architecture); but the Artificial elements have always proved too strong, and the two have never mixed. In Architecture, everything has three dimensions; and the artificial foliage is carved with leaves, etc., of a suitable thickness: in Natural foliage the tenuity of leaves, etc., is such that it cannot be reproduced. Even in the architraves round the glorious doors of Florence the natural foliage is not always a success; and where Ghiberti has stopped short in the ductile bronze, it is not probable that the modern carver will succeed in stone. It may therefore be suggested that the close imitation of Natural foliage should be confined to objects of _two_ dimensions, i.e., to plane surfaces and figured materials.

This selection of the Elements of Decoration, according to their association, is analogous to the selection made use of by the Poet, from the words and ideas, which are his Materials. It will be observed that, as on a Classic or Heroic subject, the choice is of learned words and classical ideas, and on a Domestic or Pastoral one, simple words and homely similes are used--so, in conjunction with the severe forms of Architecture, the formal character of artificial foliage is suitable; and for decorating Textiles and other movable Accessories, the Natural foliage, with which the earth is clothed and beautified, is appropriate.

ENRICHMENT OF SURFACE may be beautiful for one reason; IMITATION OF NATURE is beautiful for another. When imitations of natural foliage are introduced decoratively on a surface, then may it be twice beautiful--first, in the _principles_ according to which the distribution is arranged; and secondly, because of the _elements_ which are worked in being beautiful in themselves. Geometrical elements might be so used as to serve the first end, but can never fulfill the second: Storiation fulfills the second; but its increase of interest absorbs the first.

This course of Lectures is intended to treat of Natural foliage, leaving Artificial foliage to be dealt with at another opportunity. It is not Historical. The History of the Decorative treatment of Natural foliage, showing its evolution in the past, is a large and interesting theme; but, unless this were accompanied by critical remarks based on given principles, the method might be barren of results. Tradition is not to be undervalued; but the student should be led to Tradition through Principles.

It is further intended more especially to apply to the aesthetic use. When natural foliage is used AEsthetically (i.e., decoratively), then the Shape of the surface should govern the Mass shape of the foliage, and there should be Parallelism between them (see Sec. 29). When used Didactically (i.e., symbolically), then the foliage may be treated more freely.

Sec. 4.--THE FOUR TREATMENTS.

There are, broadly speaking, four methods of treating Natural foliage. These may be arranged in a Chart, according to their relation to the two poles of Art and Science; from Realism (which is all Art and no Science) to the "Botanical Analysis" method (in which is a little Science but no Art), thus:

The first two of these methods are Artistic and legitimate: the others are inartistic and misleading. Before treating of the artistic methods it will be well to clear the ground by dismissing the others.

ART POLE..........................................SCIENCE POLE

Realism | Conventionalism | Disguised | Botanical
(See Sec. 10). | (See Sec. 14). | Artificialism | Analysis
| | (See Sec. 6). | (See Sec. 5).

Sec. 5.--THE BOTANICAL ANALYSIS TREATMENT.

In this method the student was taught (i) to draw each plant with the Stem _straightened out_, the Leaves _flattened out_, and the Flowers represented as in _side elevation_ or _plan_. (ii) The Flowers were further _pulled in pieces_, and the Petals were _flattened out_ in a manner similar to the Entomologists' practice of displaying their "specimens" scientifically. Often, also (iii) the Stems and Buds were _cut through_; and "patterns" were made with the Sections.

With regard to the first of these practices (i): it should be observed that much of the beauty of appearance of natural foliage results from the variety of view, the subtile curvature, and the foreshortening, as seen in perspective; and that to sacrifice all these for the sake of a _diagram_ would be a wasted opportunity.

With regard to the other practices (ii) and (iii): it is obvious that these statements of the facts of the plant are useful as a part of the Science of Botany; but can no more be considered as making Decoration than Anatomical diagrams can be looked upon as Pictures. Some knowledge of external Botany is useful to a Pattern artist as some knowledge of external Anatomy is useful to the Pictorial artist. In each of these cases, the Science, which discovers and records facts, is subservient to its sister, Art, which uses the facts to interpret appearances; and, when scientific diagrams are put forth as Art, the Science is in its wrong place: it has then been treated as if it were the Building instead of being only the Scaffolding; and the results of such attempts cannot be considered as complete or final.

Examples of this method are given in Figs. 1 and 2. It was officially encouraged about twenty-five years ago; and books like "Plants, their Natural Growth and Ornamental Treatment," and "Suggestions in Floral Design," both by F. Edward Hulme, F.L.S., etc., show it at its best.

In criticising this method, there is no desire to cast any slight upon those who were responsible for it. They were groping in the dark, and did the best they knew, according to their lights. But Japanese work was not known at that time, and, but for that, the Pattern artist of to-day might still be occupied in pinning leaves and flowers against the wall. It was, moreover, a protest against the Cabbage Rose on the Hearth rug, that some may still remember with shuddering.

Sec. 6.--THE DISGUISED ARTIFICIALITY TREATMENT.

In this method the student was taught to sketch out what he considered to be good Curves and Spirals; and then (i) to bend the selected plant so that its stem might coincide with them, regardless of its own proper natural growth; or (ii) to deck out the first drawn spirals with the leaves and flowers of the selected plant.

With regard to the first of these practices: it is much more foolish than the Analysis method; and is little short of blasphemy against the Great Designer. He has determined how each plant shall grow: how, within limits of cultivation, its stems and branches shall separate, each to seek its own share of air and sunshine; how its leaves shall stand erect or droop, each according to its function; and always in perfect beauty. And further: how each family of plants shall have its own method of branching; which is as much a part of its character and often of its beauty as are the Flowers and Leaves.

The second practice, which generally produces a result similar to the first, is quite as unthinking. It is more often practiced; and is responsible for many of the labored and uninteresting designs which are common. If the Pattern-artist deck-out the old worn-out and common place spirals with leaves and flowers borrowed from Nature--the result is like the "voice of Jacob and the hands of Esau;" it is merely a Disguise of Artificiality.

An example of this method is given in Fig. 3. It was generally practiced in Germany; and books like "Das Vegetabile Ornamente," by K. Krumbholz, show it at its best.

If this treatment were universally followed--there would soon be an end to design with natural foliage. The spectator might observe one border which appeared to be a Rose, another a Tulip, the third a Thistle, and the fourth a Fuchsia; and, on examination, discover that these were not Rose, Tulip, Thistle, and Fuchsia; but merely that very artificial old friend--the Spiral-scroll--_in disguise_.

An apologist for this method remarks:--" ... In such matters as the ramification of plants, ... nature is always making angles and elbows [_sic_] which we are obliged, in decorative treatment, to change into curves for our purpose;...". This opinion needs only to be applied to animals in order to exhibit its absurdity; and with regard to plants, it will be seen that this tampering has not even the poor merit of success.

Sec. 7.--NOTE ON SYMMETRY.

A desire for Symmetry often accompanies these two treatments. This is a quality to be avoided whenever possible in Natural foliage design. The so-called "Turn-over patterns" are an economy in Weaving-design, but the economy is of the wrong kind. An artist should spend his thought to spare material or cost in working. When he spares his _thought_--making the least amount of thought cover the greatest amount of surface--then is his work worth to the world just what it has cost him, i.e., very little.

So injurious is the influence of Symmetry in Natural foliage design, that it might almost be a test question--"Is the design symmetrical?" When the exigencies of Machine-reproduction necessitate this with Natural foliage--it is a hardship which the Artist regretfully accepts, and no one would willingly make a design for Hand-reproduction which was symmetrical; rather would he spend himself to insure the worthier result which ensues from Balance.

An example of Symmetry is given in Fig. 4; and of Balance in Fig. 5. Each panel contains two classes of Elements:--Natural foliage (i.e., two branches of the Bay tree), and an Artificial object (i.e., a Ribbon which ties them). The lower Element (i.e., the Ribbon) is treated symmetrically in both panels: the higher Element (i.e., the Branches) are _symmetrical_ in the former panel, and _balanced_ in the latter. This latter treatment, will be seen to be not only the more interesting, but the more like the infinite variety of Nature; while the former is a wasted opportunity, and contrary to Nature.

The Student will observe by experience that the mind soon tires of Artificiality, both in Curvature and in Symmetry; the lines of Nature have a pleasant freshness and inexhaustible variety; and the _Natural_ method of treating Nature is not only the most true, but also the most beautiful.

Sec. 8.--REALISM AND CONVENTIONALISM: DEFINITIONS.

REALISM--the result of _Realistic_ treatment, i.e., the attempt to render the reproduction as like the reality as is possible, even to the verge of deception--is the aim of the Pictorial-Artist. In Pictures the surface appears to have been annihilated, and the spectator beholds the scene as if there were a hole through the wall. It is not the highest, and should not be the only aim in Art; but it has always been sought for and admired. It requires perfect conditions, of materials and tools; i.e., _complete Technical appliances_.

CONVENTIONALISM--the result of _incomplete Technical appliances_, and the attempt to render so much of the Beauty of the original as is possible, with due regard to their capabilities--is the aim of the Decorative-Artist. It is not the highest aim; though a necessary curb in Decorative-Art, both for the technical reason, and also as a result of the Position or Function of the object.

It will thus be seen that the two words, when used with regard to foliage of any kind, refer to the _Method of representing it_, and not to its Kind or its manner of Growth.

Sec. 9.--SCALES FROM REALISM TO CONVENTIONALISM.

These two methods, when applied absolutely, form the two extremes:--The most complete REALISM being at one end, and the most limited CONVENTIONALISM at the other. There are scales of gradual reduction between them, which may be shown on two charts:

(i) Reduction in the NUMBER OF PARTS which preserve their Realistic rendering.

(ii) Reduction in the DEGREE OF REALISM through all parts.

(i) According to the number of the features or parts of the design which are treated with less than realism. Thus there might be a panel representing a Window-opening with an architectural framing, with a Flower-vase on the sill, and a Landscape-background. The first part to be reduced in realistic rendering would be the Background, the second would be the Framing, leaving the third, the Flower-vase, as the survival. This is a Scale of reduction in _Number of Parts_.

It may be shown, in tabular arrangement, thus:--

REALISM............................................CONVENTIONALISM.

COMPLETE PICTORIAL REALISM, in which all parts are realistically
represented (see Sec. 10).

SEMI-PICTORIAL REALISM, in which the Back-ground is reduced to
a flat-tint, while all the remaining parts are realistically
represented (see Sec. 11).

DECORATIVE REALISM, in which the chief Feature (_only_)
is realistically represented, and all the other parts are
reduced to conventional renderings (see Sec. 12).

COMPLETE CONVENTIONALISM, in which all parts are reduced to
conventional renderings (see Conventionalism).

Inasmuch as there is some realistic part remaining in each of the first three methods--these are classified under the heading of REALISM.

(ii) According to the Degree in which color, gradation, or shading, is sacrificed, in consequence of the limited Means at the disposal of the Artist; resulting in the gradual departure from Realism to the most severe Conventionalism. The reduction is applied to all parts of the work. This is a scale of reduction in _Degree_. There are two Varieties in each degree; and they are marked with italic letters.

It may be shown, in tabular arrangement, thus:--

REALISM.............................................CONVENTIONALISM.

COMPLETE REALISM, in which all parts are represented, in
proper colors, and perfect gradation, with correct light and
shade (see Sec. 10).

FIRST DEGREE OF CONVENTIONALISM, in which all parts are
represented: (a) By a reduced number of Pigments, the other
qualities remaining; (b) By reduction in gradation and
shading to Flat-tints of several pigments (see Sec. 15).

SECOND DEGREE OF CONVENTIONALISM, in which all parts are
represented: (c) By a reduction to Monochrome of color, with
Gradation (_only_) remaining; (d) By reduction to Monochrome
of White and Black, with Gradation (_only_) remaining (see Sec.
16).

THIRD DEGREE OF CONVENTIONALISM, in which all parts are
represented: (e) By reduction to a Flat-tint of one pigment
on a ground of another; (f) By reduction to a Flat-tint of
White on Black, or _vice versa_ (see Sec. 17).

ULTIMATE CONVENTIONALISM, in which all parts are
represented; (g) By reduction to Outline of several
pigments; (h) Reduction to Outline of one pigment (see Sec.18).

Inasmuch as Realism ceases so soon as any reduction in the three qualities (of color, gradation, and shadow) is introduced; and the treatment becomes more Conventional in each method after the first--these are classified under the heading of CONVENTIONALISM.

[There is an analogous scale of reduction in Form, from the Complete-relief of an isolated Statue to the Flatness of a Floor-plate; but this does not belong to the present subject.]

* * * * *

THE CYCLOSTAT.

The various processes commonly employed for the observation of bodies in motion (intermittent light or vision) greatly fatigue the observer, and, as a general thing, give only images, that are difficult to examine. We are going to show how Prof. Marc Thury, upon making researches in a new direction, has succeeded in constructing an apparatus that permits of the continuous observation of a body having a rapid rotary motion. The principle of the method is of extreme simplicity.

Let us consider (Fig. 1) a mirror, A B, reflecting an object, C D, and revolving around it: when the mirror will have made a half revolution, the image, C' D', of the object will have made an entire one. The figure represents three successive positions of the mirror, distant by an eighth of a revolution. The structure of the image shows that it has made a quarter revolution in an opposite direction in each of its positions. But if (Fig. 2) the body itself has revolved in the same direction with an angular velocity double that of the mirror, its image will have described a circle in remaining constantly parallel with itself. The image will be just as insensible as the object itself; but it is very easy to bring it back to a state of rest.

Let us suppose (Fig. 3a) the observer placed at O, the revolving object at T, the axis of rotation being this time the line O F. Let us place a mirror at A B and cause it to revolve around the same axis; but, instead of looking at the image directly in the mirror, let us receive it, before and after its reflection upon A B, upon two mirrors, C D and D E, inclined 30 deg. upon the axis of rotation of the system; the image, instead of being observed directly in the mirror, A B, will always be seen in the axis, O F, and will consequently appear immovable.

The same result may be obtained (Fig. 3b) with a rectangular isosceles prism whose face, A B, serves as a mirror, while the faces, A C and B D, break the ray--the first deflecting it from the axis to throw it on the mirror, and the second throwing it back to the axis of rotation, which is at the same time the line of direction of the sight.

The principle of the instrument, then, consists in causing the revolution, around the axis of rotation of the object to be observed, of a mirror parallel with such axis, and in observing it in the axis itself after sending the image to it by two reflections or two refractions. In reality, the entire instrument is contained in the small prism above, properly mounted upon a wheel that may be revolved at will; and, in this form, it may serve, for example, to determine the rotary velocity of an inaccessible axis. For this it will suffice to modify its velocity until the axis appears to be at rest, and to apply the revolution counter to the wheel upon which the prism is mounted, or to another wheel controlling the mechanism.

But Mr. Thury has constructed a completer apparatus, the _cyclostat_ (Fig. 4), which, opposite the prism, has a second plate whose actuating wheel is mounted upon the same axis as the first, the gearing being so calculated that the prism shall revolve with twice less velocity than the second plate. This latter, observed through the prism, will be always seen at rest, and be able to serve as a support for the object that it is desired to examine.

1. General view of the apparatus. 2. Section of the ocular, O.]