“Then these are the three types of soil with which the farmer has to deal, and which we wish to understand.  For one may learn to know his garden soil by studying it, just as one learns a lesson by study.

“I believe the boys from their last winter’s work feel fairly familiar with soils, I have in these three tumblers the three types of soil.  As I pour water on them just see what happens.  Observe how little water it takes to saturate sand.  The limy soil holds more water and the clayey an amazing quantity.

“I do not know whether you are much acquainted with the sea shore, I doubt it.”

“I am,” broke in Katharine, “for each summer, except this last one, I have spent a month at the beach.”

“Then possibly you can tell us, Katharine, whether, or not, the sand takes in, or absorbs, much heat during the day.”

“Indeed it does absorb heat; why some days we used to go barefooted on the beach right after dinner.  I can tell you there were times when we couldn’t stand the heat of the sand.”

“That is quite true,” continued The Chief, “sand absorbs heat to a remarkable degree.  This heat is, to be sure, in the upper layers of the sand.  Had Katharine burrowed down with her toes below those upper layers she would have found moist, cool sands.  But an upper layer of soil, made up of particles which fall apart easily because of the loose make-up, a layer which has absorbed little water and much heat—­well, to me that sort of soil doesn’t sound quite right for good gardening.  Add to such a soil, humus in the shape of stable manure in large quantities and this same poor soil becomes very good.

“Now here is the lime soil tumbler.  This soil has taken up rather more water than the sand took.  But it, too, surely needs to develop greater power to take in and hold water.  So the same sort of medicine which we gave the sandy soil may be dealt out to the lime soil.  Lime is a pretty good substance to have in soil.  Lime is a kind of fertilizer in itself; it’s a soil sweetener; it helps to put plant food in shape for use, and causes desirable bacteria to grow.  This sounds a bit staggering but all of these things I am going to talk over with you.  So just at present forget it, Albert, if it is a heavy burden.

“The clay soil, you observe, has taken in quite a quantity of water.  That seems like a good thing.  It is.  But clay has a mean little habit of squeezing tightly its particles together with the aid of water so that air is excluded from the mass.  It forms huge lumps; it bakes out and cracks badly; and it is also very damp, cold and soggy in early spring.

“As the problem with sand is to add something so that more water may be held in the soil, so the problem with clay is to overcome that bothersome habit of baking and caking and cracking.  To do this we might add sand or ashes.  But perhaps it would be better yet to add manure with a lot of straw in it.  This is the easiest kind of thing for country boys and girls to get, because the bedding swept out of horses’ stalls is just the thing.