Chapter 8

In the earliest the round arch was used, but the later and more perfect styles having employed the pointed arch almost exclusively, the latter became characteristic of Gothic art generally. It is a style of architecture and ornament usually applied to churches, and well adapted to moist and cold climates on account of the sloping roof. Clustered columns, the spire or belfry, the arched roof, and the division of the interior into nave, transept, and choir, are leading features. Natural as well as conventional treatment of plants is another important characteristic.

The Gothic style flourished principally in England, France, and parts of Germany. Nearly all the principal cathedrals and churches in these countries, and many in our own, are built after this style. The most beautiful example in this country is St. Patrick's Cathedral, in New York. The finest specimen in the world is probably the Cathedral of Cologne, which was commenced in the 14th century, but was not completed until many years later.

III. MODERN ART.

In the 15th century a remarkable revival occurred in literature and the fine arts, showing a decided tendency to return to the old classic ideas of the Greeks and Romans. After an almost complete neglect, which lasted for centuries, artists and men of letters turned their attention to the long neglected relics of pagan civilization as worthy of study for their intrinsic beauty alone. Symbolism was relegated to a minor position, and beauty was once more cultivated for its own sake. This epoch is termed the Renaissance--which literally means a rebirth or revival.

1. _Renaissance Style._--The term Renaissance is also applied to one of the early styles which came into vogue at this time. It flourished principally in southern Europe. It is not a pure style, but marks a transition period from the old popular Gothic and Saracenic forms to the revivified classic. It naturally exhibits a queer mixture of conflicting elements--classic and mediæval thrown together without much regard to propriety or fitness. It still showed traces of symbolism.

2. _The Cinquecento Style._--The Renaissance reached its most perfect development in the Cinquecento or the 15th century style. It followed the Quatrocento or 14th century style. Entirely untrammeled by symbolism, and with the whole field of classic and mediæval ornament to glean from, its aim was to develop a perfect style of ornament. The best examples of this period are founded on the soundest principles of ornamental art. Nothing that could be turned into an element of beauty was neglected. Animals, real and fictitious, flowers, leaves, fruit, the human form, etc., were conventionalized and made to contribute their part to enhance the beauty of the whole. Some of the principal characteristics of the Cinquecento style are the delicate arabesque scroll work, the profusion and beauty of the curves, its admirable variations of standard classic ornaments, such as the anthemion and scroll. The coloring, also, was one of its most pleasing features. This style flourished principally in Italy and France. Farnese Palace and the tombs of the Medicis are noted examples.

3. _The Louis Quatorze._--This style succeeded the Cinquecento, but was far inferior to it. It arose in Italy, and while preserving generally the materials of the style that preceded it, it added as characteristic features the scroll and the shell. Its principal object was to create brilliant and startling effects in light and shade. Color was, in consequence, decidedly secondary, gilding being used everywhere. The Palace of Versailles, near Paris, is a gorgeous example of this style. Everything in it is glittering and sparkling. Mirrors are everywhere placed to intensify this effect. This style was followed by the Louis Quinze, inferior to it in every respect, and in which symmetry, at least in detail, seems to be carefully avoided. It still further degenerated into the Rococo, the most extravagant and exaggerated of all the historic styles, and which prevailed in the latter part of the 18th and the beginning of the 19th century.

The present century cannot boast of any great characteristic style in either architecture or ornament. Whether it is only in a course of development, and what will be the results, time only can show. All styles are now in vogue, hence the importance of accurate knowledge on the subject. To be able to judge of and appreciate the best, and to profit by the labors of those gone before us, at the same time imparting individuality and character to our own design, should be the aim and object of the study of decoration, and it should enter into any scheme of general education and culture.--_Journal of Education_.

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THE MONTAUD ACCUMULATOR.

This accumulator is of the Plante type, and is modified so as to obtain a more rapid formation, a larger surface, and a symmetrical distance of the plates from each other. If into an alkaline bath saturated with litharge (added in excess) we plunge two lead electrodes and pass in a current of suitable tension and intensity, there is deposited upon the anode a layer of peroxide of lead varying in thickness with the intensity of the current, and more or less rich in oxygen according to the intensity of the bath, while the cathode is covered with a stratum of reduced lead. The liquid of the bath supplies material for both deposits, while in galvanoplastic operations the anode supplies it to the cathode. The principle of the formation consists in introducing in an efficacious manner currents of a great intensity, and thus abridging its duration.

Of two plates thus treated, the one becomes positive, and is covered with a thick layer of peroxide of lead. On leaving the bath it undergoes various preparations and several washings, and is then fit to be mounted along with others to form an accumulator ready to be charged and to work. The second, or negative, plate is covered with a thick sponge of lead. It is carefully washed, preserved in water with exclusion of air, and submitted to a very considerable pressure. After this operation it presents the appearance of ordinary sheet lead, but though the physical porosity has disappeared, the chemical porosity is intact, and this alone comes into play in accumulators. When a negative plate is constructed in this manner, it is ready to be combined with the positives to form an accumulator.

The inventor has sometimes put into the bath at the positive pole negative plates prepared as just described. They become very easily peroxidized, but they have the grave defect of requiring two preparations in place of one. To secure an accumulator against any leakage from plate, the solderings and the entire plates must be submerged in the liquid, so that nothing projects up out of the acidulated water except two strong rods for making contact. These rods are covered with an insulating varnish from their origin to above the point where they issue from the liquid. The plates are of a rectangular form (Fig. 1). They are sloped out at one corner, and as two plates in juxtaposition are cut together, when they are separated the sloping out of the one serves for the handle of the other. This handle is doubled back on the plate which is suspended in the bath, so that the part which has to be soldered does not undergo any preparation. A hole pierced in this corner of the plate serves to receive a square rod of lead, which connects the plates together and supports one of the poles or contacts of the accumulator. At the point of soldering the doubled-down handle gives a double thickness, and the margins of the plate are folded in such a manner as to insure their solidity.

The sloped out corner affords the free space necessary for the rod of the opposite pole, and one and the same plate may be indifferently connected either to the + or the - at the right or the left. The plates are made of four different sizes: No. 1, 19 of which serve for an accumulator of 1 square meter; No. 2, 21, 25, or 29 of which serve for accumulators of 2, 3, and 4 square meters; No. 3, which with 21, 25, or 29 plates composes accumulators of 5, 6, and 7 square meters; and No. 4, which with 21, 23, 25, 27 or 29 plates forms accumulators of 8, 9, 10, 11, and 12 square meters.

As the plates are entirely submerged in the liquid their entire surface is active, and the entire surface being absolutely flat, it is sufficient to preserve their respective distance at any one point in order to have it everywhere alike. The weight of the plate depends on the intended duration of the plate and its capacity. As for the negative plate, its thickness is the most important factor of its capacity. The proportion has yet to be established for daily practice. The inventor uses in practice positive plates of 0.002 meter in thickness. On the other hand, the negative plates have a body of only 0.001 meter in thickness, their greater thickness being due only to the deposit of compressed lead. The rod which fixes the plate to each pole (Fig. 2) is formed of a special alloy of lead and antimony, not attacked by acid. This gives rigidity to the rod, and hinders it from binding when the accumulator is taken out of its case. The copper piece which surmounts it is fitted at its base with an iron cramp, which is fixed in the lead, and above which is a wide furrow with two grooved parts, which being immersed in the lead hinders the copper from slipping round under the action of the screw. The rod is square, and is cast in a single piece. Against one of its surfaces the ends of the connected plates press flatly up. A square form has been selected to give more surface for soldering. The soldering is autogenous (as in the lead chambers at vitriol works). The soldering, as well as the entire plates, is entirely immersed in the liquid, and to prevent any leakage an insulating varnish, perfectly proof against the acid and the current, is laid over the rod from the part soldered upward.

If it is wished to lift the accumulator from its chest for any verification, hooks passing between the plates seize hold of the rods, and thanks to the rigidity of the antimony lead, they effect the removal of the apparatus without bending the rods in the least. All the parts of the plates must be kept at exactly the same reciprocal distances, and a difference of only 0.001 meter between two points is sufficient to affect the yield considerably. For an insulating material, wood, when plunged in dilute acid, is preferred by the inventor. He makes a comb of wood, the teeth of which vary according to the thickness of the plates to be lodged between them. Fig. 3 represents a comb having 15/10 of a millimeter for the negative plates and 25/10 for the positive plates.

This appliance, which is 0.01 meter in thickness and 0.02 meter in width in the back, is made very cheaply by machinery. The weight of the accumulator bears entirely upon the back of the combs, which are all placed back downward, and the number of which varies according to the size of the plates. Small combs of wood clasp the plates at their extremities, and make the entire accumulator quite compact and manageable. The entire accumulator is shut up in a wooden chest, which the outer teeth of the comb serve to insulate from the leaden chest, and to prevent any loss of electricity along the sides.

Fig. 4 shows the arrangement of the side combs. A single glance at this figure shows that it would be difficult to have more surface without having recourse to curved, undulated, or folded plates, in which the distances are variable, and consequently defective. In the Montaud accumulator, the weight is simply proportional to the intended duration. For the notion, "So much capacity and so much yield per kilo.," Montaud substitutes the notion, "So much capacity or yield per square meter, the weight not being taken into consideration." These Montaud accumulators are classified as follows: They have from 1 to 12 square meters of surface, and the number corresponding to the surface indicates its weight of useful lead, its manner of charging, its capacity, and its manner of discharge.

According to the inventor's experiments, the square meter of active surface can receive a charging current of 10 amperes, and furnish on discharging a current of the intensity of 20 amperes. For a "No. 10" accumulator we have an active surface of 10 square meters, a charging current of 100 amperes, and on discharging a current of 200 amperes. A square meter of lead of the thickness of 0.001 meter weighs about 11 kilos.

As both surfaces of the lead are utilized, their weight is reduced to 5½ kilos. A No. 10 therefore requires 55 kilos. of useful lead. It will be seen that to increase the thickness of the sheet of lead merely augments the duration of the accumulator, without affecting its capacity or its manner of charging and discharging. Nos. 1, 2, 3, and 4 may be placed in vessels of stoneware, glass, or ebonite, or in boxes of pitch pine, painted with three coats of gum lac and lined with sheet lead. Nos. 5 to 12 are only sent out in pitch pine boxes lined with lead. The box is supported on feet of porcelain of the shape of a mushroom. If a drop of water falls upon this foot, it cannot give a communication with the earth, since, falling upon the broad part of the mushroom, it will glide off without running along the foot, which serves as the stalk of the mushroom. A slip of glass is placed under each foot; the part which supports the mushroom is covered with an insulating varnish, which prevents the formation of climbing salts and preserves the screws from rust. A common layer of insulating varnish is applied under the head of the mushroom.

As regards the advantages of the Montaud accumulator we notice, first, its longevity. Dr. D'Arsonval points out that the accumulators of the Plante class have a great advantage over the Faure type as regards duration, and that the most striking quality of the Montaud accumulator is its longevity. The inventor has in his possession positive plates, five to six years old, completely peroxidized, though there remains in the interior a thin core of metallic lead sufficient to give passage to the current. The adhesion of the peroxide is such that to detach it, it must be beaten with a hammer upon an anvil. The next four points--i.e., the rapidity of charge; the yield, much greater than that of any other system in proportion to its surface; its small weight in comparison with its yield; and its capacity, which for an equal weight is greater than that of any other accumulator. In his experiments in September, 1885, Dr. D'Arsonval obtained with an accumulator of 2 square meters of surface:

Useful capacity 40 ampere hours. Total 62 " " Surface 2 square meters Charge 10 amp. per sq. meter. Discharge 20 " " " Useful weight of lead 10 kilos.

Representing a total capacity of six ampere hours per kilo., and of a discharge of 5 amperes per kilo., or a total capacity of 81 ampere hours per square meter, and a useful capacity of 20 ampere hours per square meter. Subsequently the modification of the negative plate has greatly improved these figures, which will certainly become much more advantageous in future. The total capacity of an accumulator having exactly 1¾ meters of surface has become 87 ampere hours, which if referred to an accumulator of 2 square meters of surface, would give the following results:

Useful weight of lead per sq. meter 5½ kilos. Total capacity of useful lead per kilo 9.1 amp. hr. Total capacity per sq. meter 50 " Useful capacity of per kilo of useful lead 6.23 " Useful capacity per square meter 34.30 " Current of charge per square meter 10 amp. Current of charge per kilo, of useful lead 2 " Current of discharge per sq. meter 20 " Current of discharge per kilo, of useful lead 4.56 "

The next advantage of the Montaud accumulator is the ease with which it can be taken out of its box and repaired without special tools and experience. A capital defect in this respect has hitherto much interfered with the use of accumulators. In case of accidents, several kinds of which are possible, it is found very difficult to rectify the apparatus. The Montaud accumulator is much less liable to accidents, on account of the firmness and compactness of its construction, and if any accident happens, the repairs are simple and easy. Lastly, the stout framework secures the apparatus from any accident due to a disproportionate charge or discharge. The peculiarities of the combs and rods already described solve this problem. On September 8, 1885, Dr. D'Arsonval, professor at the College of France, wrote as follows: "The Montaud accumulator is of the Plante type, and is extremely well conceived from a mechanical point of view. The wooden combs prevent the plates from coming in mutual contact, and give the apparatus great solidity. The process of formation is ingenious and rapid. To give 1 square meter a capacity of 20 ampere hours, there is required only a quarter of an hour's treatment.

"To obtain the same result by Plante's method, months are required. The entire experiments have been effected with No. 2, which has a surface of two square meters. This apparatus, if charged to saturation, gives 62 ampere hours as its total capacity, and, as in the Plante, this capacity constantly increases with use. The normal rule for the charge is 10 amperes per square meter, and for the discharge double this quantity. This apparatus has always given me on discharging 40 amperes at the E.M.F. of 1.85 volts during 60 or 65 minutes. The charge is effected in two hours up to 20 amperes, without any appreciable loss of electricity.

"The points to be aimed at in an accumulator are longevity and energy, or, rather, rapid yield per kilo. From both points of view accumulators of the Plante type (and consequently those of Montaud) are far superior to those of the Faure type. My opinion, therefore, is that the Montaud accumulator is very practical, that it is a great improvement on the Plante type, and that it can compete successfully with the other systems in use."--_Revue Internationale de l'Electricite._

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ELECTRIC REGISTERING APPARATUS FOR METEOROLOGICAL INSTRUMENTS.

Mr. E. Gime, whose name is not unknown to our readers, sends us a description of a certain number of meteorological apparatus to which he has applied a peculiar method of registering that it is of interest to make known.

Mr. Gime in the first place has devised a "telemareograph," that is to say, an apparatus designed to register at a distance the curve of the motions of the tide in a given place. The structure of this device, shown diagramatically in Fig. 1, is very simple. It is divided into two distinct parts--a transmitter and a registering apparatus. The transmitter consists of a long glass tube, A, closed at one end and communicating through the other with a receptacle filled with mercury. A barometric vacuum is formed in this tube. The level of the open receptacle corresponds exactly to the level of the lowest tide.

Pieces of iron wire projecting sufficiently in the interior to establish good contacts with the column of mercury are fastened one millimeter apart to the inner surface of the tube. These iron contacts are connected with the divisions of a rheostat, R, arranged in a tight compartment surrounded with paraffine, near the tube.

This rheostat is interposed in the general circuit. It is connected through one extremity with the line, and through the other with a disk of copper, which has a surface of one square meter, and is immersed in the sea.

The line, L, insulated like an ordinary telegraph wire, is prolonged as far as to the registering station.

The registering apparatus consists of a solenoid, S, that acts upon a soft iron core suspended by a cord from the extremity, _x_, of the beam of a balance. This cord passes between the channels of two rollers designed, despite the motion of the beam, to keep the core in a vertical position in the center of the solenoid.

The opposite arm of the balance carries a sliding weight, _i_, that moves over a graduated scale and is designed to balance the core, N, in a certain position in regulating the motions of the curve. At its extremity it carries a style that bears against the drum, T, on which the paper is wound that is to receive the mareometric curve.

The solenoid, S, is interposed in the general circuit, being connected on the one hand with the line, L, and on the other with a very constant battery of an electromotive force proportioned to the resistance of the circuit.

Through the electrode that remains free, the battery is grounded with so great care that no variation in resistance can be produced thereby. If the station is near the sea, the conductor of this electrode may be run to a copper disk, having the same surface as the one at the transmitting station. With this description, the operation of the apparatus may be easily understood.

At low water, the pressure of the atmosphere balances a column of mercury rising in a glass tube to a height proportionate to such pressure. In measure as the level of the water rises, the pressure on the mercury in the receptacle increases, and causes the metal to rise in the tube. The higher the level of the sea, the less becomes the sum of the resistances of the rheostat, since the column of mercury puts in short circuit all the divisions of the rheostat, whose contacts are comprised in the height of the column.

From these variations in the resistance of the circuit naturally result variations in the current from the battery, B, at the registering station. To the variations in intensity of the current in the circuit there correspond variations in the attraction of the solenoid for the core that transmits these motions to the balance that carries the registering style, which latter amplifies or reduces them.

The same transmitter suffices for various registering stations arranged in series, as shown in Fig. 2.

The variations in the resistance of the circuit, due to variations in the temperature, and the variations in the height of the column of mercury, due to atmospheric variations, etc., are, according to the inventor, of no importance.

It would evidently be possible, on the same principle, to construct an apparatus for registering the indications of a thermometer at a distance.

Such is the principle of Mr. Gime's apparatus. We do not believe that they are entirely closed to criticism. What, in fact, are the conditions essential for their proper working? Evidently: (1) the constancy of the battery used; (2) a rigorously accurate adjustment. This latter condition, is easily realized; but the same is not the case with the former. Of what elements shall this constant battery be formed?