Then, too, there were great changes in temperature. First everything was heated to a high temperature, then gradually became cool. Just think of the cracking, the crumbling, the upheavals, that such changes must have caused! You know some of the effects in winter of sudden freezes and thaws. But the little examples of bursting water pipes and broken pitchers are as nothing to what was happening in the world during those days. The water and the gases in the atmosphere helped along this crumbling work.

From all this action of rubbing, which action we call mechanical, it is easy enough to understand how sand was formed. This represents one of the great divisions of soil sandy soil. The sea shores are great masses of pure sand. If soil were nothing but broken rock masses then indeed it would be very poor and unproductive. But the early forms of animal and vegetable life decaying became a part of the rock mass and a better soil resulted. So the soils we speak of as sandy soils have mixed with the sand other matter, sometimes clay, sometimes vegetable matter or humus, and often animal waste.

Clay brings us right to another class of soils clayey soils. It happens that certain portions of rock masses became dissolved when water trickled over them and heat was plenty and abundant. This dissolution took place largely because there is in the air a certain gas called carbon dioxide or carbonic acid gas. This gas attacks and changes certain substances in rocks. Sometimes you see great rocks with portions sticking up looking as if they had been eaten away. Carbonic acid did this. It changed this eaten part into something else which we call clay. A change like this is not mechanical but chemical. The difference in the two kinds of change is just this: in the one case of sand, where a mechanical change went on, you still have just what you started with, save that the size of the mass is smaller. You started with a big rock, and ended with little particles of sand. But you had no different kind of rock in the end. Mechanical action might be illustrated with a piece of lump sugar. Let the sugar represent a big mass of rock. Break up the sugar, and even the smallest bit is sugar. It is just so with the rock mass; but in the case of a chemical change you start with one thing and end with another. You started with a big mass of rock which had in it a portion that became changed by the acid acting on it. It ended in being an entirely different thing which we call clay. So in the case of chemical change a certain something is started with and in the end we have an entirely different thing. The clay soils are often called mud soils because of the amount of water used in their formation.

The third sort of soil which we farm people have to deal with is lime soil. Remember we are thinking of soils from the farm point of view. This soil of course ordinarily was formed from limestone. Just as soon as one thing is mentioned about which we know nothing, another comes up of which we are just as ignorant. And so a whole chain of questions follows. Now you are probably saying within yourselves, how was limestone first formed?

At one time ages ago the lower animal and plant forms picked from the water particles of lime. With the lime they formed skeletons or houses about themselves as protection from larger animals. Coral is representative of this class of skeleton-forming animal.

As the animal died the skeleton remained. Great masses of this living matter pressed all together, after ages, formed limestone. Some limestones are still in such shape that the shelly formation is still visible. Marble, another limestone, is somewhat crystalline in character. Another well-known limestone is chalk. Perhaps you’d like to know a way of always being able to tell limestone. Drop a little of this acid on some lime. See how it bubbles and fizzles. Then drop some on this chalk and on the marble, too. The same bubbling takes place. So lime must be in these three structures. One does not have to buy a special acid for this work, for even the household acids like vinegar will cause the same result.

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.

But we will now suppose that it is possible to really choose just the right site for the garden. What shall be chosen? The greatest determining factor is the sun. No one would have a north corner, unless it were absolutely forced upon him; because, while north corners do for ferns, certain wild flowers, and begonias, they are of little use as spots for a general garden.

If possible, choose the ideal spot a southern exposure. Here the sun lies warm all day long. When the garden is thus located the rows of vegetables and flowers should run north and south. Thus placed, the plants receive the sun’s rays all the morning on the eastern side, and all the afternoon on the western side. One ought not to have any lopsided plants with such an arrangement.

Suppose the garden faces southeast. In this case the western sun is out of the problem. In order to get the best distribution of sunlight run the rows northwest and southeast.

The idea is to get the most sunlight as evenly distributed as possible for the longest period of time. From the lopsided growth of window plants it is easy enough to see the effect on plants of poorly distributed light. So if you use a little diagram remembering that you wish the sun to shine part of the day on one side of the plants and part on the other, you can juggle out any situation. The southern exposure gives the ideal case because the sun gives half time nearly to each side. A northern exposure may mean an almost entire cut-off from sunlight; while northeastern and southwestern places always get uneven distribution of sun’s rays, no matter how carefully this is planned.

The garden, if possible, should be planned out on paper. The plan is a great help when the real planting time comes. It saves time and unnecessary buying of seed.

New garden spots are likely to be found in two conditions: they are covered either with turf or with rubbish. In large garden areas the ground is ploughed and the sod turned under; but in small gardens remove the sod. How to take off the sod in the best manner is the next question. Stake and line off the garden spot. The line gives an accurate and straight course to follow. Cut the edges with the spade all along the line. If the area is a small one, say four feet by eighteen or twenty, this is an easy matter. Such a narrow strip may be marked off like a checkerboard, the sod cut through with the spade, and easily removed. This could be done in two long strips cut lengthwise of the strip. When the turf is cut through, roll it right up like a roll of carpet.

But suppose the garden plot is large. Then divide this up into strips a foot wide and take off the sod as before. What shall be done with the sod? Do not throw it away for it is full of richness, although not quite in available form. So pack the sod grass side down one square on another. Leave it to rot and to weather. When rotted it makes a fine fertilizer. Such a pile of rotting vegetable matter is called a compost pile. All through the summer add any old green vegetable matter to this. In the fall put the autumn leaves on. A fine lot of goodness is being fixed for another season.

Even when the garden is large enough to plough, I would pick out the largest pieces of sod rather than have them turned under. Go over the ploughed space, pick out the pieces of sod, shake them well and pack them up in a compost heap.

Mere spading of the ground is not sufficient. The soil is still left in lumps. Always as one spades one should break up the big lumps. But even so the ground is in no shape for planting. Ground must be very fine indeed to plant in, because seeds can get very close indeed to fine particles of soil. But the large lumps leave large spaces which no tiny root hair can penetrate. A seed is left stranded in a perfect waste when planted in chunks of soil. A baby surrounded with great pieces of beefsteak would starve. A seed among large lumps of soil is in a similar situation. The spade never can do this work of pulverizing soil. But the rake can. That’s the value of the rake. It is a great lump breaker, but will not do for large lumps. If the soil still has large lumps in it take the hoe.

Many people handle the hoe awkwardly. The chief work of this implement is to rid the soil of weeds and stir up the top surface. It is used in summer to form that mulch of dust so valuable in retaining moisture in the soil. I often see people as if they were going to chop into atoms everything around. Hoeing should never be such vigorous exercise as that. Spading is vigorous, hard work, but not hoeing and raking.

After lumps are broken use the rake to make the bed fine and smooth. Now the great piece of work is done.