A Caricature is a pictorial representation in which the beauties are concealed and the peculiarities or defects exaggerated to make the person or thing ridiculous, while a general likeness is retained. 
Although caricature may be applied to all objects, the human face and figure are the most susceptible to treatment, the most interesting and convenient to study; and he who masters the difficulties of facial expression and the action of the human figure will find other objects comparatively easy. [124-25]
In addition to exaggerating certain facts, good caricaturists omit much. Therefore, a caricaturist’s first step is to determine what peculiarities are predominant in the person or object he is attempting to ridicule, and in what way these can be exaggerated to produce the most humorous effect. A practical caricaturist knows by experience just what to do the minute he looks at an object he intends to draw in a humorous way; and while definite rules cannot always be laid down, it is safe to say that, in case of some well-known character, for instance, a heavy percentage of comic artists working independent of each other would seize upon the same salient characteristics as a butt for their humor.
A fertile field for the imagination of the caricaturist, and one which has in the past been explored to good advantage, is the combination of a man’s characteristics, mental or physical, with those of an animal which he seems to typify . . . . Then, too, the human figure can be made to suggest other objects in an effective way. Thomas Nast, the great caricaturist of the past generation, represented Tweed as a human bag of money. Some faces, particularly those of beautiful women, are difficult, almost impossible, to caricature.
A commonly used device in a case of this kind is to reduce the size of the body and to bring into prominence by exaggeration any individual peculiarity of dress or manners which may be characteristic of the subject. 
A cartoon is a picture (either a caricature or a symbolical composition) designed to advocate or attack some political or other idea of present interest or some prominent person. It may or may not be a caricature. Many well-known paintings are virtually cartoons. G. F. Watts’ Love and Death and other great masterpieces are examples of this. But the usually accepted idea of a cartoon is the pictorial com-positions we see in our daily papers caricaturing some prominent person or idea. 
[The editorial cartoonist’s resources, and what an editorial cartoonist should know] Added to the sense of humor, the cartoonist should have a general idea of the political situation through-out the countries of the world. He should also be reasonably familiar with what is happening in society and financial circles. A knowledge of history, mythology, and the Bible will not come amiss, but, most of all, he must have what is termed “a nose for news” and the ability to rapidly convert important news-topics into crisp, logical, convincing pictorial sermons. The mere ability to draw an ill-proportioned face does not constitute a good comic artist, or even touch the outskirts of good cartooning.
Each accessory of a properly conceived cartoon should bring out its chief point, and anything added beyond this is an element of weakness. The picture should convey one idea strongly, and at the first glance. [136-37]
Mr. W. A. Rogers, the New York Herald’s brilliant cartoonist, says: “After all, we cartoonists are merely reporters with a drawing pen or brush instead of a pencil. But we must follow the news as closely as any editor. Our news sense — that much-abused term — must be as keen. . . . Often a cartoonist must edit a page of political news into a narrow column cut, or reduce a column of news into a single line. . . . Well, I can’t afford to miss the news of a single day.”
There are usually one or two prominent news items each day acceptable for treatment as cartoons. Sudden war, a runaway bank cashier, a bit of important election news, are examples of hundreds of happenings that furnish pertinent suggestions for satirical picture-editorials. 
Wright, Grant. The Art of Caricature. New York: Baker & Taylor, 1904. Internet Archive online version of a copy in the Getty Research Institute. 19 June 2019.
Last modified 22 June 2019