replied miss mary let us now reason about the the small hole will only let through a quarter part as much water as the large one with the same pressure and of course there must be four times as much pressure to make the same quantity of water pass yes said and so the water must rise four times as high believe so said miss mary that is if four times the height of water would make exactly four times the pressure and i believe it would now i think the water cannot rise four times as high without going over the top of the board and of course you cannot with this dam get a pressure sufficient to carry all the water through that opening it is running over interrupted james j see it is running over it was beginning to run over a little here and there along the edge of the board a� water james said had careful when he put the board down to make the upper edge as nearly level as he could get it and then when he came up from his work the first night after it had been made he stopped a moment to look at it to see if the water was running over it equally he found by the running of the water that one end of the board was a little higher than the other and he drove it down a little with his axe and then the water glided over the edge of the board in one regular sheet of equal thickness from end to end and now therefore when the water began to run over it began in various places all along the edge of the board at the same time the jet from the small hole was away with very considerable force carrying off a large portion of the water but not the whole i wish said that my dam was a little higher and then perhaps the water would rise high enough to force it all through the small hole couldn t you put another board on said miss mary o yes said jumping up and clap blowing his hands we will james we will if you will wait here miss mary for ii james and i will go up immediately and ge board miss mary promised to wait and so and james set off towards the house they however took the measure of the length so that the board should fit to its place when they got up to the house they found a board very easily but they had some difficulty in it off neither nor james being much accustomed to the use of the saw worked upon it for a time and when he was tired he gave the saw to james however they got it off at length and then they took it one boy at each end and carried it down to the dam then they placed it very carefully upon the top of the other board pressing it down hard upon it and letting it lean back against the which had driven in aad which were long enough to support this additional board as well as the one first put down the whole operation seemed to succeed perfectly the new board was not so wide as the er it was not more than five or six water inches wide while the other was nearly a foot still they thought it would be wide enough it will raise the water half a foot said and that will put a great deal more pressure on but they found that the two boards did t ot fit together very well and some water escaped through the crack between them endeavored to drive the upper board down closer to the lower one by striking the upper edge of it with a sort of club which he picked up upon the bank he did in this way make the of the boards somewhat closer but still some water would find its way through however notwithstanding this they soon found that the water was slowly rising up the side of the upper board and of course as the depth increased the pressure increased too and the jet of water from the hole which was near the bottom of it was thrown out with greater and greater force they all thought that probably before the water got as high as to the top of the upper board the pressure would be great enough to force it out as fast from the hole as it can in from blowing the brook above and it is very possible thai it might have been so had not the progress of the experiment been interrupted in a manner the dam and this was the way they were standing together near the bank looking at the jet of water which was away beautifully to a considerable distance down the stream when james who had been looking down into the water said suddenly � o see that little stick sailing round and round looked down where james pointed and saw a small stick slowly revolving in the water in the comer near one end of the dam close in by the bank both and miss mary watched it for several minutes wondering what could make it move in that curious way the stick faster and faster and presently there seemed to be a small depression in the water and a little leaf which was floating near began to move round in the same way it is a little said miss mary yes said what a beautiful little n what makes it miss mary i don t know said miss mary i i have often seen such little in the water though not generally in such still water as this it grows bigger said it was indeed growing a little bigger the depression in the centre became deeper and the little sticks and 