A Stream. A stream is best not attempted where the operation is small. In the natural rock garden of considerable area, especially if there are different elevations, it may be introduced with charming results. If a series of small pools are constructed at different levels, with a winding rivulet connecting them, no great flow of water will be required. It may be made to appear very much longer than it is if hidden here and there by a skillfully arranged bit of planting. Where it is concealed from view, it will have the effect of leisurely meandering about, and then coming back into sight again.
Waterfalls. A waterfall, even though it may be very small, will add the charm of both motion and sound to the garden picture. A mere trickle of water falling from a slight elevation into a pool below will accomplish this, if one provides the means of making the tiny stream actually fall through the air, instead of running down over the stones. The trick necessary to produce this result is shown in one of the accompanying illustrations. The water is conducted to a point or points, whence it must really drop off, by affixing to the ledge of stone over which it flows bits of rough concrete a few inches long, and cone shaped; these will usually become covered in due time with moss or water plants.
The Moraine. The moraine is mentioned here because it is referred to in most rock-garden literature, particularly in that from the "other side," and occasionally in catalogs. A moraine is a sort of cross between a rock garden and a bog garden. It is exceptionally well drained and dry on the surface, but with water available beneath.
There are a few plants which require this combination of conditions to do their best. The majority, however, can be grown satisfactorily without creating this special form of rock-water garden for them. The beginner, therefore, need not include the moraine among the things he has to worry about in getting a start with rock gardening. The Bog Garden.