- t much experience with the ma terial world and the people who move in it one cannot go far in the exercise of the higher function of judgment, reason and restrained, emotions. One has but to visual ize the ordinary schoolroom in which pupils commonly receive eight or possibly 12 years of their formal education to be convinced that there are forceful arguments in favor of a larger introduction of the visual means of instruction. Even when the picture exprc,,scs but a small part of the idea to be presented it may often serve as a suitable starting point about which to build a group of related thoughts.
There is need for recognizing the fact that visual representations like language vary greatly in significance, expressiveness and other respects. rules of grammar and rhetoric have been fully developed and stated. It is understood that words should be selected and combined with a view to precision, clearness and force. There are rather definite standards for judging the value of oral and written speech. But there is still much cardessness and indifference in the selection and use of picture expression. This condition probably grows largely out of the fact that pictures are so often used merely as supplementary to the lan guage form of expression, that they are com monly prepared by inferior mechanical pro- . cesses and by persons not thoroughly acquainted with the ideas to be expressed and that those who are supposed to learn from them are con tent with a very superficial observation of them. The chief standards for selection and use of pictures are their authenticity, truthful ness, expressiveness, quality and attractiveness, When a verbal statement is made one prop erly asks what authority there is for it? What weight can be attached to it? So with a pic ture one should want to lcnow its source. What evidence is there to show that it expresses what is purported? There is particular need for applying this standard to pictures used to illustrate history. On any adequate test many of those appearing in books on history would be found altogether unreliable. The pictures have been thrown in to catch the eye but with out having been as critically examined as the text.
A picture may be attractive but untruthful. This is particularly likely to be the case with fanciful drawings where the illustrator lacked specific knowledge of the subject or was in different to the criterion of truthfulness. A
picture may of course be authentic and yet not truthful, for example, a reproduction of Leutze's 'Washington Crossing the Delaware.) A challenging attitude Should be assumed toward a picture both as to its authenticity and its truthfulness. In the matter of expressive ness pictures of all sorts vary as much as do verbal expressions. There is much trash in pictures. Many of them have little significance, while some are worth long study. A picture that is full of significance commands repeated attention. In education the selection of pic tures is largely a work of elimination.
The quality of pictorial expression should be judged as critically as that of verbal ex pression. There is no more excuse for care lessness and indifference in one case than in the other. Rarely does a pOorly made photograph or drawing actually give full and accurate expression. A picture is defective to the de gree to whith the observer is unable to see in it the idea intended to be expressed. Many factors, including quality, enter into the at tractiveness of a picture. While a pleasing ap pearance is very desirable it should not obscure the importance of the other factors. The tend ency is to produce merely an appeal to the eye rather than to the mind.
As to forms or types pictures may be classed as prints, lantern slides and films. Prints are pictures or drawings made by transfer from engraved plates, lithographic stones, photo graphic negatives or the like. They are used in boolcs, magazines, pamphlets and other publi cations or appear alone. A stereograph is a pair of photographic prints made in a particu lar way. They bring out the third dimension or depth better than the single print. They are of advantage only where perspective is an important feature to be observed.
Obviously a print is suitable for individual study rather than for class instruction. It is usually too small to .be observed by several persons at the same time.
A lantern slide is a photographic positive on a glass plate. The image is projected upon a screen giving a picture sufficiently large for effective instruction. Slides are pre-eminently the form of pictures suitable for class use for instruction by visual means. The attention of every member of a class or audience can be directed to the same thing at any moment, which is essential to class instruction, and there is ample opportunity for close observation and discussion.