Harry

They were driven close to land, and they were obliged to go on shorethe shore was sandy, and there grew near the place where these men landed a great deal of sea weed. The men wanted to boil some food in an iron pot, whicb they had brought on shore with them; they made a fire on the sands with sea¬weed ; and tbey observed,, , , , , that the ashes of this sea weed, mixed with the sand and burned by the fire, had a glassy appearance. It looked like a kind of greenish glass. It is said, that from this observation they formed the first idea of ma¬king glass by burning ashes of sea weed (called kelp) and sand together."How lucky it was, that they made this fire on the sand with sea weed!" said Harry.

How wise these people were, to observe what happened when they did so!" said Harry's father.

NEXT morning, when Harry and Lucy went into their father's room, Harry began with his usual speech Now for the barometer, papa!and," added he, , , ,,we must make baste, for we are to go to morrow to my uncle's, and I must understand k quite, before I see him againwe must make haste, papa."Let us go on quietly from where we left off yesterday," said his father.Yes, about the long pipe," said Harry.Pray, papa," said Lucy, when you were speaking of the water staying in the pipe, why did you say, that the water would be held up, or sustained, by the pressure of the atmos¬phere, to thirty three or thirty four feet high in the tube ?

Why should you say thirty three or thirty»four feet?Would it not stay either at the one or at "the other of these heights?"That is a very sensible question, Lucy," said her father. u The reason is, that the pressure of the atmosphere is not always the same. , , , , , In fine weather, it is generally greater, than when it rains or snows, and before it rains or snows, the pressure or, as it is sometimes called, the weight of the atmosphere, is less than at some other times. So that, if we had such a pipe, or tube, and if the upper part of it were transparent, so that we could see into the inside of it, we could tell, try the rising and falling of the water in the pipe, when the air, or atmosphere, was heavier or lighter, and then we might suppose, that the weather was going to change. I say suppose, because we should not be sure."