The learner should go over and work out each of the foregoing problems several times. In fact, until they are soundly secured in his memory, so that on any emergency he can apply them to a required practice. They are the simplest rudiments, but as practically useful as they are simple. The Architect, the builder, as well as the several trades of carpenter, joiner, carver, stone-cutter, mason, and in fact, all in any way concerned in the practice of construction will at some time or other wish to recall one of these useful problems. Therefore do we dwell on the necessity for committing them, understandingly, to memory, and likewise the advantage required in being able to draw them neatly and perfectly on paper. In order to do this with satisfaction to one’s self, it is desirable that a fine point be constantly maintained on the pencil, and that uniform nicety be preserved with the curved lines, as well as the right or straight lines. For nothing looks worse than undue thickness in the one or the other. All should be alike. In theoretical geometry a line, whether right or curved, is but imaginary, not having any thickness whatever, and therefore no palpable existence. In practical geometry the line must be visible, but ought to be so uniformly fine as to occupy scarcely any perceptible thickness. And herein lies the greatest beauty in geometrical draughting. By strict attention to this apparently trifling matter, its advantages will show wherever minute angles occur. They will be clear and distinct, and always satisfactory. The learner should keep his first attempts, however coarse, for they will by comparison hereafter, show the advance he has made. Nor should he be content to “let well enough alone.” There is no “well enough” in drawing. It is a progressive science, and the true artist never believes he has done his best. Go as near to perfection as you can, and do not turn aside from, or step over obstacles to reach the end you have in view. Whatever you have neglected in early study will surely haunt you through after years, and trouble you when you can least bear the annoyance. We now conclude this primary lesson, hoping that our learners may profit by the hints we have thrown out, and will thoroughly prepare themselves for the advance in our next. * * * * * THE first brick house in Iowa was built by Judge Rerer, of Burlington, in 1839. VINES FOR THE DECORATION OF COTTAGES. THE GROUND NUT VINE.