This then is the programme of work which must be adopted by any serious aspirant to fame in the art of the painter, and it is perhaps not surprising that the number of artists who survive the ordeal is strictly limited. In any walk of life where years of struggle are necessary for success, how small the proportion of men who persevere to the end; who present a steel wall to misfortune and despair, and with an indomitable will, overcome care, and worry, and fatigue, for year after year, till at last the clouds disappear, and they are able to front the world with an all-powerful shield of radiant knowledge! But unfortunately in the painter's art it is difficult to convince students of the necessity for long and hard study, because there is no definite standard for measuring success or failure which they can grasp without long experience. In industries where knowledge is applied to improvement in appliances, or methods with definite ends, or to the realization of projects having a fixed scope, failure is determined by material results measured commonly by mathematical processes of one kind or another. A man produces a new alloy which he claims will fulfil a certain purpose. It is tested by recognized means: all concerned admit the validity of the test, and there the matter ends. But in the arts, while the relative value of the respective grades is equally capable of demonstration, the test is of a different kind. Instead of weights and measures which every man can apply, general experience must be brought in. The individual may be right in his judgment, and commonly is, but he is unable to measure the evidence of his senses by material demonstration, and as he has no means of judging whether his senses are normal, except by comparison, he is liable to doubt his own experience if it clash with that of others. Thus, he may find but little beauty in a given picture, and then may read or hear that the work has a high æsthetic value, and without calling to mind the fact that no evidence in the matter is conclusive unless it be based on general experience, he is liable to believe that his own perception is in some way deficient.