The black bottle being empty, we all drew a long breath-and wished it were full.

"Come away," said the Engineer. "Jenkins will start her; I'm tired."

The bell rang as we left the engine-room. The terrible noise recommenced, and science, under the guidance of Jenkins, once more impelled us forward at a conservative rate.

"O that Dn were here to see!" I exclaimed, taking the Engineer's arm.

"O that he were here to feel!" was his rejoinder, the thermometer being at 154°.

I looked steadfastly upon my companion. He did not appear to advantage. It would not be too much to say that science had used him up. Moreover, he was manifestly disgusted with circumstances. "D- -n is a great man," he said. "Wait till I fill this bottle, and we'll talk it over."

I waited. We nourished ourselves. Then we sat down on a guncarriage and this is what the Engineer said:

"D- -n is a great man. I've read his Washington speech, all about the Navy, and I know by that his mighty intellect. He's acquainted with Lord Byron's verses, and with Pope and Shakspeare; and he knows all about Mariotte's Law. This is one of his engineswith the

cut-off. It makes 35 revolutions a minute, and it

also makes a splendid noise. These are the least of its merits. It is an admirable consumer of oil. I suppose D-n learned the value of lubrication when he was a lawyer and used to oil the bench. The usual allowance to this engine is five gallons an hour-which is'nt enough, and so the boys smuggle it on, at the rate of about a hundred and twenty-five gallons.a-day. All the journals require it constantly (no pun intended). And then the firemen! It keeps them as busy as bees, because, you know, if the cut-off should become deranged-as I do sometimes, for instance-and steam should be used at full stroke on the engines, then the expansion application, through good fires, would rest entirely upon them. That

is clear, is'nt it? When the engine is used at full stroke, and there are fifteen pounds of steam in the boilers, five revolutions will reduce the pressure to nine pounds. This again shows the wonderful utility of the cut-off, which saves the expense of large boilers for marine engines. Dn, as 1 said before, is a great man-a gigantic and tremendous man. I have read his tribute to Watt (E), and Watt, if he wots any thing about it, ought to be very grateful for such a first-class notice; and I have read also his remarks on expansion. And, trusting in D-n, I don't see why a donkey-boiler would'nt do for this ship, just as well as the two big ones that we carry now. But that's a point for science to determine, after we've got rid of the superfluous coal."

At this point the Engineer's remarks were interrupted by a sudden commotion in the engine-room, wherefrom, presently, several men emerged, bearing the insensible body of an oiler who had just fainted among the dash-pots. They carried him away.

"It occurs frequently," resumed my companion. "Even Dn himself became a victim once-in Jerome's yacht, I think. Science

D

must have its martyrs, you know. I've lost several fingers myself, tripping valves; and I know three engineers who, while on duty, have dropped insensible at their posts. You will notice that our stokers are very like skeletons. Thin men stand the heat better than fat ones; and the thermometer in our engine-room rarely marks less than 140°. This is another of the beauties of the cut-off-it paves the way to promotion in the service, by cutting off so many human obstacles."

Here my companion (or was I deceived in the dim moonlight?) deliberately winked upon me with one eye. Then, seizing the black bottle, he drank, with his mouth, for some time. Finally he resumed his remarks:

"Dn is a modest man, too. All great genius exhibits that characteristic. He never blows his own horn. He said once, that he 'was profoundly ignorant of a steam-engine, and supposed a cylinderhead to be a full moon.' That was modesty! No one, who has ever heard our cylinders work, would credit it of him. They suggest any thing but moons. Meteors, accompanied by thunder, would much better typify them. But whatever may be the great man's notion as to cylinder-heads, he has certainly got very clear ideas on the subject of DASH-POTS. Look at that engine, for instance! It's all over dashpots. They gleam like the brass kettle of by-gone days, in which my venerated and now defunct grandmother used to boil cabbage. Hence the tender associations with which they are fraught. I look upon them, day and night, with never-tiring admiration (F). The rings of Saturn and the splendors of Mars are really as nothing to these irridescent vehicles of science. I have, indeed, commenced a poem about them-in humble imitation of the great engineer's favorite bard. It will be comprised in four hundred cantos, commencing thus:

"There is, however, another feature in this engine, which illustrates to still greater advantage the grandeur of D-n's inventive genius. That is, the LINK-MOTION. The lustre of this device outshines even

the lustre of the dash-pots. You have just seen something of its achievements in starting this ship. It is not, like the common and vulgar link-motion in general use, an instantaneously adjustible apparatus, easily worked by one man. On the contrary, it requires only about fifteen men to work it, and it keeps them occupied from ten to twenty minutes in adjusting the various cogs, and cranks, and levers, in conjunction with the cut-off machinery, for going ahead or backing. Plainly enough, science marks this link-motion for its own. Only a man who, like D- -n, had read 'Richard the Third,' and 'drank of the pure fountain at its source,' could have devised it. So ponderous is the mass of metal employed, that it necessitates a huge weight, acting-on a principle of sweet simplicity-over a pulley, and attached to the upper part of the arcs of both engines, thereby to lessen what otherwise would be a terrible strain on the ship. I am sure you will

sympathize with my admiration for this triumph of skill. There is a great gain, too, in noise by this means-noise so salutary in its impression on the common mind. A free space is made for these weights to run up and down inside the coal bunkers; and so, at the slightest motion of the ship, they create a most exhilarating clatter, harmonizing with the delicious din of the entire engine.

"These little touches evince the philosopher. Common minds would have been content with celerity, safety, and economy, without reference to the ornamental intricacies of science. Not so the expansive D- -n. His progress in the realms of thought bears no distant analogy to the wise man's progress in the realms of experience. Youth imagines that the world was made for man. Maturity discovers that man was made for the world. So in mechanism. To the budding and innocent Dn of long ago, it seemed, no doubt, that dash-pots were made for engines. To the full-blown D -n of to-day, it is manifestly clear that engines were made for dash-pots. Hence the noble machinery, with its patent cut-off and astonishing link-motion, that we have here the privilege to observe. It has been constructed under the white light of science, and without the slightest regard to expense. Its dash-pots gleam, in the yellow radiance of polished brass, and its monkey-tails are marshalled like the Assyrian cohorts of the pious Byron. Great facilities are afforded for the soothing influence of oil, and for the consequent liberal dissemination of postal currency and green-backed notes. The whistle is a dear one; but Uncle Samuel (like the old trump that he has always been) pays for it without a murmur, and wins the unqualified approbation of DCould more be wished? I leave it to your judgment as a citizen.

-n.

"You have observed-doubtless with profound amazement-the striking ceremonies with which it is necessary to approach this engine,