One mistake very often made by men who have not carried their studies far enough is to miss the necessary connexion between the state of the sea and the accompanying condition of the atmosphere; another is to paint in a sea picture a sky that is in wrong relation to the wave movement. Both these errors arise from the failure of the painter to study his subject as a whole, from his inexperience of what may be called the technical peculiarities of his material. He has by him a sea note that seems worth treating on a more ambitious scale, and he finds in his portfolio a sketch of a sky that composes nicely and is quite attractive in its general character; so he mixes the two together and calls the compilation a marine painting. But, really, unless by some lucky chance the two sketches happened to have been done under similar weather conditions the picture would be no more true to nature than the laboured effort of the “art” photographer who prints his sky from one negative and his landscape from another; or who grafts a studio-lighted figure on to a background photographed out of doors. The sea painter must, for the credit of art, keep clear of such silly tricks and mechanical devices. He must be logical both in his observations and in the use he makes of them, and he must be consistent in his statement of the facts before him. A picture in which the sea suggests half a gale while the sky is one which would be seen only in a dead calm is an obvious absurdity, and it would be not less ridiculous to paint the full colours of sunlight in an atmosphere of mist and driving rain; yet these things are done by artists from whom more regard for truth is to be expected. Lapses of this sort cannot be forgiven; they imply a shirking of responsibility that is beyond excuse, and a failure to grasp the first principles of nature study. They would never occur if the men who paint the sea would regard it as a living reality which responds to the influence of its surroundings and varies its appearance as circumstances dictate, and if they would recognize that it has its own anatomical structure by which its movements are controlled. There is a reason for everything it does and there is a way of accounting for every aspect it assumes, but the reason has to be sought for, and the way to necessary knowledge must be pursued with painstaking effort. There is no place in marine painting for the man who wants to take things easily.