CHAPTER THIRTY.
MY MEASURING-RULE.
The details of my plan suggested themselves in the following order:--
While examining the cask, to find if there was not some means ofascertaining its different diameters, I discovered the very way itself.All I wanted was a straight rod or stick, of sufficient length to reachquite across the butt at its thickest part. It was plain to me, that byinserting such a stick into a hole in one side of the cask, and passingit on till it touched the staves on the other side, at a pointdiametrically opposite, I could thus obtain the exact measurement of thediameter of that part of the vessel, since the portion of the rodreaching from side to side would be the diameter itself. The diameteronce obtained, it needed only to multiply by three to get thecircumference. But in the calculation which I was desirous of making,it was the diameter itself I wanted to find, and not the circumference.I only thought of the latter, because, under ordinary circumstances,when a cask is bunged up, it is easier to measure the circumference ofthe swell than its diameter. In no case does it signify which, as thefigure three will always reduce the one to the other, near enough formost practical purposes, though not mathematically exact.
Now, it so chanced that one of the holes I had cut through the staveshad been made in the very middle of the swell, where the butt wasthickest. Therefore a straight stick passed into this hole, and pushedon till it touched the opposite side, would give the greatest diameterof the cask.
You may imagine that this might have been obtained by simply plantingthe stick in a vertical position _outside_ the butt, and notching it ata point on a level with the top of the vessel. True, this might havebeen done had I been operating with a barrel lying upon a plain surface,with nothing around it to obstruct me, and plenty of light to observethe true level. Even thus it would have been rough guess work, and notto be depended on when a calculation was to be made involving life ordeath in its consequences--for such it really did involve--at least, Isupposed so. But the butt was so placed, resting upon the timbers ofthe ship, with its swollen side sunk between them, that I could not havemeasured it in this manner. Even though I might have marked a rod on aline with its top, I could not have planted the other end so as to be ona level with its base.
There seemed no other way to get at the thing than by inserting astraight stick into the hole, and thus measure the diameter; nor did Itrouble myself about any other, as this appeared to be the best plan Icould adopt.
Where was I to find my stick--my measuring-rule? That is your question,is it not?
It is easily answered. The deal board that had formed part of thebiscuit-box would supply me with the material, and out of that I couldsoon make one. No sooner thought of than I set about it.
The board was but a little over two feet in length, and of course notlong enough to reach across the great cask, which at its thickest partappeared four or five. But a very little ingenuity sufficed to overcomethis obstacle. I should only have to split off three thin pieces, andby splicing their ends together, I should get a stick of lengthsufficient.
I did so. Fortunately, the deal was cut nicely with the grain of thewood; and in splitting it, I guided the blade of my knife so as not tolet it run out at the edges.
I succeeded in getting three pieces of the thickness I wanted; and,after shaving off their angles, and making them clean and trim, I cuttheir ends with a slant for the splice.
The next thing was to obtain two pieces of string, and this was theeasiest thing in the world. I wore upon my feet a pair of little"buskins" that laced up to the very ankle. The laces were thongs ofcalfskin, each of them a full yard long. They were just the thing; and,drawing them out of the holes, I completed the splicing, and now held inmy hands a straight stick full five feet in length--quite long enough, Iconceived, to reach across the thickest part of the butt, and slenderenough to go into the hole--which I had already widened a little toreceive it.
"So far good," thought I; "I shall now insert the measuring-stick, andfind my diameter."
I rose to my feet to carry out this design, but I need not describe themortification I felt on perceiving that the first of these operations,which would appear to be the simplest of all, could not be performed.At the first trial I saw that it was quite impossible. It was notbecause the hole was too small, or the stick too large. I had made nomistake about this; but my miscalculation was in regard to the space inwhich I had to work. Lengthways my little chamber was nearly six feet,but crossways little more than two; and up where the hole was--in whichI intended to insert the measuring-rod--it was still less. Of course toget the stiff piece of stick into the cask was plainly impossible--without bending it, so that it must break--for the dry deal would havesnapped through like the shank of a clay pipe.
I was a good deal chagrined at not having thought of this before; but Iwas still more vexed at the idea of being obliged to abandon the designof making the measurement I had intended, for before reflecting Ibelieved that this was to be the result. A little furtherconsideration, however, helped to a new plan, proving the importance ofnot arriving too hastily at conclusions. I discovered a way of gettingin the stick to its full length, without either breaking or bending it.
This could be effected by taking it to pieces again, then firstinserting one of the pieces, and holding it till the second could bespliced on to its end, and then pushing both into the cask, and joiningthe third piece in a similar fashion.
About this there appeared no difficulty, and the result proved there wasnone; for in less than five minutes after conceiving it, I had carriedthe design into execution, and the measuring-rod stood inside thebarrel, with one end projecting some inches on the outside.
Holding this end carefully in my hand, I caused the other to play abouton the opposite side, until I felt convinced that it touched the pointthat was exactly _vis-a-vis_ with the aperture; and then steadying thestick, I notched it with my knife, on a level with the outer surface ofthe stave. To calculate from this notch would not be correct, as itwould be more than the diameter of the cask--that is, in reference towhat it would contain--but I had no intention of doing so. I shouldmake allowance for the thickness of the stave, and that would give methe measurement I wanted.
Having made my mark, I drew forth my measuring-rod, piece by piece, asit had been plunged in. I took care as I did so to notch both thesplices, so that I might be able to put them together again in the exactplace where they had been while making the measurement. All thisattention to such minute particulars was of importance, and I knew it tobe so, for the mistake of even a quarter of an inch in the length of mydiameter would cause a difference of many gallons in the result. Mostcertainly, then, was it of consequence that I should be precise in my_data_.
I now had the diameter of the swell; the next thing was to get that ofthe head, or end. About this there was less difficulty--in fact, notany. It was obtained in a few seconds.
Though I could not myself get round either of the ends of the butt, noreven my arm, I could pass the rod around them, and in this way measurethem. Even had there not been space to admit the measuring-stick, Ishould have found a means--by simply drilling another hole with myknife, close to either end, and gauging as before. But this would haveoccupied time, and it was not necessary to do so, since the stick passedalong the head of the butt without any obstruction, till its end restedagainst the projecting rim on the opposite side. I had nothing to dobut assure myself that its point was fair in the middle, and then makemy mark as before.
The length of the butt was yet to be ascertained; and this, thoughapparently a simple operation, cost me a good deal of consideration,before I could get at it with any degree of exactness. You may fancythat it would have been easy enough to get at the length, by justplacing the stick parallel to the cask, and notching it square with theends of the latter? And so it might be easy enough, with plenty oflight around you to see when it _was_ square, and a level surface uponwhich to rest your measure. But as I had the advan
tage neither of lightnor level ground, I encountered great difficulty in this operation. Icould not tell when the ends lay even with each other, merely by thetouch. I had to pass my fingers from one to the other, and could notgrasp both at one time--that is, the rim of the cask and the end of therod--since they must needs be several inches apart. The stick, too, layunsteady, and by the feel I could not be sure when its end was exactly"flush" with the head of the cask. The mistake of an inch--it might beseveral--would falsify all my computations, and render them of no use.It would not do to proceed upon such a conjectural basis, and for awhile I was puzzled, and had to pause.
This was an unexpected obstacle, for I had from the first regarded thediameters as the only difficulty; about the possibility of obtaining thelength, I had never entertained a doubt.
But my wits again came to the rescue, and I soon discovered a plan thatwould effect the end in view. I had to make another rod--by splicingtwo more lengths split from the board--and with this I was able todetermine the point.
I managed the matter thus: The old rod I pushed along the head of thecask quite beyond its outer edge, so that it rested at both ends againstthe projecting rim. Thus placed, it was exactly parallel with the planeof the barrel's head, while a foot or more projected outward and towardsme. Holding the end of the second rod against this projecting part, andat right angles, I gave it a direction along the side of the cask, and Iwas able to mark the point, where the middle part of the swell came incontact with the second rod. This, of course, after deducting the depthof the rim and the presumed thickness of the head, gave me half thelength of the interior of the cask, and that was all I wanted, since twohalves make one whole.
I was now in possession of the _data_ of my problem; it only remainedfor me to seek the solution.