"Well, then, if by any method whatever I increase the volume of that quant.i.ty of water by pouring in yet more through the mouth of the little tube; the water thus compelled to flow downwards would rise in the reservoir, represented by the flower-pot, until it reached the same level at either end."

"That is quite clear," cried Raphael.

"But there is this difference," the other went on. "Suppose that the thin column of water poured into the little vertical tube there exerts a force equal, say, to a pound weight, for instance, its action will be punctually communicated to the great body of the liquid, and will be transmitted to every part of the surface represented by the water in the flower-pot so that at the surface there will be a thousand columns of water, every one pressing upwards as if they were impelled by a force equal to that which compels the liquid to descend in the vertical tube; and of necessity they reproduce here," said Planchette, indicating to Raphael the top of the flower-pot, "the force introduced over there, a thousand-fold," and the man of science pointed out to the marquis the upright wooden pipe set in the clay.

"That is quite simple," said Raphael.

Planchette smiled again.

"In other words," he went on, with the mathematician's natural stubborn propensity for logic, "in order to resist the force of the incoming water, it would be necessary to exert, upon every part of the large surface, a force equal to that brought into action in the vertical column, but with this difference--if the column of liquid is a foot in height, the thousand little columns of the wide surface will only have a very slight elevating power.

"Now," said Planchette, as he gave a fillip to his bits of stick, "let us replace this funny little apparatus by steel tubes of suitable strength and dimensions; and if you cover the liquid surface of the reservoir with a strong sliding plate of metal, and if to this metal plate you oppose another, solid enough and strong enough to resist any test; if, furthermore, you give me the power of continually adding water to the volume of liquid contents by means of the little vertical tube, the object fixed between the two solid metal plates must of necessity yield to the tremendous crushing force which indefinitely compresses it.

The method of continually pouring in water through a little tube, like the manner of communicating force through the volume of the liquid to a small metal plate, is an absurdly primitive mechanical device. A brace of pistons and a few valves would do it all. Do you perceive, my dear sir," he said taking Valentin by the arm, "there is scarcely a substance in existence that would not be compelled to dilate when fixed in between these two indefinitely resisting surfaces?"

"What! the author of the _Lettres provinciales_ invented it?" Raphael exclaimed.

"He and no other, sir. The science of mechanics knows no simpler nor more beautiful contrivance. The opposite principle, the capacity of expansion possessed by water, has brought the steam-engine into being. But water will only expand up to a certain point, while its incompressibility, being a force in a manner negative, is, of necessity, infinite."

"If this skin is expanded," said Raphael, "I promise you to erect a colossal statue to Blaise Pascal; to found a prize of a hundred thousand francs to be offered every ten years for the solution of the grandest problem of mechanical science effected during the interval; to find dowries for all your cousins and second cousins, and finally to build an asylum on purpose for impoverished or insane mathematicians."

"That would be exceedingly useful," Planchette replied. "We will go to Spieghalter to-morrow, sir," he continued, with the serenity of a man living on a plane wholly intellectual. "That distinguished mechanic has just completed, after my own designs, an improved mechanical arrangement by which a child could get a thousand trusses of hay inside his cap."

"Then good-bye till to-morrow."

"Till to-morrow, sir."

"Talk of mechanics!" cried Raphael; "isn't it the greatest of the sciences? The other fellow with his onagers, cla.s.sifications, ducks, and species, and his phials full of bottled monstrosities, is at best only fit for a billiard-marker in a saloon."

The next morning Raphael went off in great spirits to find Planchette, and together they set out for the Rue de la Sante--auspicious appellation! Arrived at Spieghalter's, the young man found himself in a vast foundry; his eyes lighted upon a mult.i.tude of glowing and roaring furnaces. There was a storm of sparks, a deluge of nails, an ocean of pistons, vices, levers, valves, girders, files, and nuts; a sea of melted metal, baulks of timber and bar-steel. Iron filings filled your throat. There was iron in the atmosphere; the men were covered with it; everything reeked of iron. The iron seemed to be a living organism; it became a fluid, moved, and seemed to shape itself intelligently after every fashion, to obey the worker's every caprice. Through the uproar made by the bellows, the crescendo of the falling hammers, and the shrill sounds of the lathes that drew groans from the steel, Raphael pa.s.sed into a large, clean, and airy place where he was able to inspect at his leisure the great press that Planchette had told him about. He admired the cast-iron beams, as one might call them, and the twin bars of steel coupled together with indestructible bolts.

"If you were to give seven rapid turns to that crank," said Spieghalter, pointing out a beam of polished steel, "you would make a steel bar spurt out in thousands of jets, that would get into your legs like needles."

"The deuce!" exclaimed Raphael.

Planchette himself slipped the piece of skin between the metal plates of the all-powerful press; and, brimful of the certainty of a scientific conviction, he worked the crank energetically.

"Lie flat, all of you; we are dead men!" thundered Spieghalter, as he himself fell p.r.o.ne on the floor.

A hideous shrieking sound rang through the workshops. The water in the machine had broken the chamber, and now spouted out in a jet of incalculable force; luckily it went in the direction of an old furnace, which was overthrown, enveloped and carried away by a waterspout.

"Ha!" remarked Planchette serenely, "the piece of skin is as safe and sound as my eye. There was a flaw in your reservoir somewhere, or a crevice in the large tube----"

"No, no; I know my reservoir. The devil is in your contrivance, sir; you can take it away," and the German pounced upon a smith's hammer, flung the skin down on an anvil, and, with all the strength that rage gives, dealt the talisman the most formidable blow that had ever resounded through his workshops.

"There is not so much as a mark on it!" said Planchette, stroking the perverse bit of skin.

The workmen hurried in. The foreman took the skin and buried it in the glowing coal of a forge, while, in a semi-circle round the fire, they all awaited the action of a huge pair of bellows. Raphael, Spieghalter, and Professor Planchette stood in the midst of the grimy expectant crowd. Raphael, looking round on faces dusted over with iron filings, white eyes, greasy blackened clothing, and hairy chests, could have fancied himself transported into the wild nocturnal world of German ballad poetry. After the skin had been in the fire for ten minutes, the foreman pulled it out with a pair of pincers.

"Hand it over to me," said Raphael.

The foreman held it out by way of a joke. The Marquis readily handled it; it was cool and flexible between his fingers. An exclamation of alarm went up; the workmen fled in terror. Valentin was left alone with Planchette in the empty workshop.

"There is certainly something infernal in the thing!" cried Raphael, in desperation. "Is no human power able to give me one more day of existence?"

"I made a mistake, sir," said the mathematician, with a penitent expression; "we ought to have subjected that peculiar skin to the action of a rolling machine. Where could my eyes have been when I suggested compression!"

"It was I that asked for it," Raphael answered.

The mathematician heaved a sigh of relief, like a culprit acquitted by a dozen jurors. Still, the strange problem afforded by the skin interested him; he meditated a moment, and then remarked:

"This unknown material ought to be treated chemically by re-agents. Let us call on j.a.phet--perhaps the chemist may have better luck than the mechanic."

Valentin urged his horse into a rapid trot, hoping to find the chemist, the celebrated j.a.phet, in his laboratory.

"Well, old friend," Planchette began, seeing j.a.phet in his armchair, examining a precipitate; "how goes chemistry?"

"Gone to sleep. Nothing new at all. The Academie, however, has recognized the existence of salicine, but salicine, asparagine, vauqueline, and digitaline are not really discoveries----"

"Since you cannot invent substances," said Raphael, "you are obliged to fall back on inventing names."

"Most emphatically true, young man."

"Here," said Planchette, addressing the chemist, "try to a.n.a.lyze this composition; if you can extract any element whatever from it, I christen it diaboline beforehand, for we have just smashed a hydraulic press in trying to compress it."

"Let's see! let's have a look at it!" cried the delighted chemist; "it may, perhaps, be a fresh element."

"It is simply a piece of the skin of an a.s.s, sir," said Raphael.

"Sir!" said the ill.u.s.trious chemist sternly.

"I am not joking," the Marquis answered, laying the piece of skin before him.

Baron j.a.phet applied the nervous fibres of his tongue to the skin; he had skill in thus detecting salts, acids, alkalis, and gases. After several experiments, he remarked:

"No taste whatever! Come, we will give it a little fluoric acid to drink."

Subjected to the influence of this ready solvent of animal tissue, the skin underwent no change whatsoever.

"It is not s.h.a.green at all!" the chemist cried. "We will treat this unknown mystery as a mineral, and try its mettle by dropping it in a crucible where I have at this moment some red potash."

j.a.phet went out, and returned almost immediately.

"Allow me to cut away a bit of this strange substance, sir," he said to Raphael; "it is so extraordinary----"

"A bit!" exclaimed Raphael; "not so much as a hair's-breadth. You may try, though," he added, half banteringly, half sadly.

The chemist broke a razor in his desire to cut the skin; he tried to break it by a powerful electric shock; next he submitted it to the influence of a galvanic battery; but all the thunderbolts his science wotted of fell harmless on the dreadful talisman.

It was seven o'clock in the evening. Planchette, j.a.phet, and Raphael, unaware of the flight of time, were awaiting the outcome of a final experiment. The Magic Skin emerged triumphant from a formidable encounter in which it had been engaged with a considerable quant.i.ty of chloride of nitrogen.