grades are recommended with the assurance that they have proved acceptable in practice and of course have introduced decided economies in construction and care.

If the reader will take the time to study the floor plans of buildings from all parts of the country reproduced in this volume, he will get an approximate idea of the prevailing standards now carried out in practice.

It must be held in mind, however, that the figures given are for classrooms of buildings designed for the elementary grades only. Classrooms for high-school buildings should not be so standardized, because of the varied sizes of classes to be taught. Each building for high-school classes should have several sizes of recitation rooms, lecture rooms, and special rooms of various kinds, and the proper dimensions of these can only be determined by a careful study of the courses offered. It is very poor economy to teach a small class in advanced Latin, mathematics, or any other subject in a classroom large enough for four times the number of students. This, however, is often done, because the architect or the one responsible for the planning did not make a careful study of what high-school students do, and how the number of pupils are proportioned to the subjects offered. Manifestly, however, the general hygienic requirements set forth for elementary students should be adhered to for high-school students.

Elsewhere in this bulletin attention has been called to the fact that there should be considerable variety in the sizes of the highschool classrooms, both from the point of view of the economy of building upkeep and care and also from the point of view of the teacher. Objection has been raised by a teacher, let us say in Latin, to going from her regular classroom where she may have most of her references books, maps, charts, etc., into a small room for an advanced class; but in reality there is very little trouble about this, for such helps as are actually needed are not troublesome to supply nor to segregate from those needed by the general classes. Ordinarily, however, in large high schools several rooms are needed for instruction in each of the major subjects of the curriculum, and the handling of classes and supplies is correspondingly simple. Economically speaking it is a mistake to allow classrooms to be idle several periods a week simply because they are marked as rooms for mathematics, English, Latin or other subjects. Teachers sometimes are considerably disturbed, even disgruntled, when "their rooms" are of necessity used for classes in other subjects. Their contentions run about as follows: "This is my room with my books, references, charts, maps, and at times board work which should not be disturbed. I need some time to prepare my work for the class and naturally the best place to do that is in my classroom, hence there

must be several periods in which my classroom is not to be occupied by any class." There is an element of truth and propriety in the foregoing statement, but most of the difficulties suggested can be eliminated by supplying departmental office rooms, library rooms, and study halls which are necessary for all large high schools. In general, then, at least three sizes of classrooms-not including laboratories and study halls-should be provided in large high schools. The largest of these should be designated for not more than 35 to 40 students, the middle size for about 20, and the smallest for about 10. Architects may easily plan buildings to meet these demands if those who are in charge of the schools will make such studies of their classes and class rolls as will set forth actual needs.

With this variety in sizes of actual classrooms there will be no need for excuse for shifting partitions or introducing the abomination of folding doors.

By reference to a number of the floor plans for high schools reproduced in this volume it will be seen that some variety in size of classrooms prevails. Generally speaking, however, buildings designed for not more than 300 or 400 students show less variation in this regard than those designed for larger numbers. This could have been anticipated on the basis of practical demands. Elective courses and increasing emphasis on sciences, English literature, modern languages, and commercial branches have broken up all first, second, and especially third and fourth year classes into smaller groups than was formerly the case. Here again, then, architects and school boards must consult teachers and study curricula and class registrations in order to plan conveniently and economically. The classrooms and recitation rooms of high schools can not be standardized in regard to amount of floor space as can those for elementary schools.

(b) LENGTH OF ROOM.

A classroom must not be so long that a pupil seated in the back of the room will have any difficulty, even with good light, in seeing easily and distinctly any ordinarily clear writing or drawing which the teacher may place upon the board in the front of the room, or such charts and models as are often used for the instruction of the whole class. It has been found by careful experimentation that the distance at which a normal eye can easily see well-written or printed letters an inch and a half high is about 29 feet. Burgerstein says: "According to my experience the distance at which a normal eye can see script 4 centimeters high, written rather heavily on a blackboard, is 9 meters (29 feet)." He concludes that it would be a good thing, therefore, to limit the maximum length of a schoolroom to 9 meters.

(Handbuch der Schulhygiene, Burgerstein and Netolitzky, second edition, 1902, p. 116.)

Burgerstein says in a later book that, all things considered, one will find that a classroom 9 meters (29 feet) long, 6 meters (19 feet) broad, and 4 meters (little over 13 feet) high is about the proper size for serviceable use. (Schulhygiene [Aus Natur und Geisteswelt], 1906, Leo Burgerstein, p. 31.)

He says such a room will accommodate double benches for 50 pupils. His reasons for this size of room are normal requirements for vision, hearing, and the depth to which light will carry.

Schmid-Monnard and Schmidt practically agree with Burgerstein. They suggest that the width might be extended to 6 meters (21 feet 4 inches). (Schulgesundheitspflege, Ein Handbuch für Lehrer, Ärzte und Verwaltungs-Beamte. Leipzig, 1902. p. 14.)

A room of this length will make it easy for a child who sits in a rear seat to hear distinctly when the teacher at the other end of the room speaks in a clear, distinct voice with moderate force and natural intonation. In the primary grades especially a large part of the instruction must of necessity be given orally, and since the children must hear the words of the mother tongue accurately if they are expected to learn to speak them correctly, it is of vital importance that their classrooms be adjusted to this demand. Unfortunately, many teachers have failed to cultivate a speaking voice that will carry well and at the same time maintain a good tone with distinctPoor spelling frequently results from inaccurate pronunciation and faulty articulation. This defect in school work was made clear by the investigations of Miss Wiltse, who found poor hearing responsible for much bad spelling. (Proc. National Education Association, 1892.)

ness.

It has been found by observation and careful investigation that the ordinary speaking voice, such as should be used in a schoolroom, will not carry with sufficient force beyond 30 feet to enable normal children to hear easily and accurately. It is very tiresome to have to strive to hear what is said, and the fatigue resulting from continued effort to hear is harmfully annoying and distracting. Furthermore, no teacher should be kept in a schoolroom that makes it necessary for her to tire her voice unduly or waste her time in repeating. Hence 30 feet is a safe length for hearing, vision, and the number of children properly in charge of one teacher.

In the length proposed I have allowed "ample room" for blackboard workers, for aisles, and for tables at the teacher's end of the room. By leaving an aisle 30 inches wide behind the last row of seats the pupils farthest from the teacher are well within hearing and seeing distance. In a shorter room there would not be space enough

for passing and for work at the board, and especially so if, as often happens, the cloakroom must be placed adjoining the rear end of the classroom. Figure 2 illustrates a room of the length and width proposed, with the location of desks, the width of aisles, and the space at the teacher's end of the room.

(c) WIDTH OF THE ROOM.

The width of the schoolroom, where unilateral lighting is used, should never exceed twice the distance from the floor to the top of the windows, and where external conditions are unfavorable for good light even this width is too great. Most European authorities insist that the width of the room should not be greater than one and onehalf times the distance from the floor to the top of the windows, and this demand is repeated by those already quoted. Naturally the row of desks farthest removed from the windows will receive the least light, but by grouping the desks as close to the windows as sufficient aisle space will permit, my experience is that in most parts of our country 22 feet is not too great a width. This will permit ample space for 35 to 40 single desks and still leave room for aisles, space for the teacher, apparatus, and the workers at the blackboards. However, one must not forget that light decreases as the square of the distance increases, and that those pupils removed the greatest distance from the light are those, other things equal, who need most attention when matters touching light are considered. Fortunately, our country as a whole is better situated with reference to latitude. than most European countries, especially England, Scandinavia, Germany, and Holland. In these countries the winter days are very short and the early morning and the afternoon light is dull and weak. We can get, on the average, better light during the winter season in a room 22 feet wide with the same dimensions of window surface than most European countries can get with one 18 feet wide. I am certain that this is true for all the southern and for most of the western part of our country.

(d) HEIGHT OF CEILING.

The height of a standard classroom should be determined after due consideration of several factors. In the first place, the item of expense should be considered. Unless some real permanent and important pedagogic or architectural ends are to be gained, every foot saved in the height will reduce the cost much more than a casual calculation would indicate. If the building is to be constructed of brick, stone, or concrete, the cost of every foot increases with the height above the ground. For instance, if a 35-foot wall is required for the basement and two stories of classrooms, 1 foot more added to each story would cost more than a foot of the same wall lower in

the building would cost. The cost would also be increased under certain conditions by reason of the need of making heavier walls, taller chimneys, longer and larger air ducts for heating and ventilation, and more extensive plumbing. Besides, every foot added to the height of a classroom adds so much more expense in keeping it in repair, and especially in heating it.

The item of expense is not, however, the most important factor for consideration, though it should not be minimized. Every foot added to the height of the interior walls of a schoolroom lifts the floor of the story above 1 foot, thereby increasing the length of stairways and making it necessary for all pupils whose classrooms are above the first floor to climb that much higher. From the hygienic point of view there is no special disadvantage in this for the boys, but it is an added hardship on adolescent girls. In case of fire or earthquake there is also increased danger. There is also a loss of time. If climbing stairs is disagreeable and tiresome to anæmic pupils, they will frequently remain in the classrooms during intermissions rather than go into the fresh air. Besides all these considerations the matter of acoustics deserves attention. Echoes are very distressing in any public assembly room, but they are serious disturbances in classrooms. Other things equal, rooms with tall ceilings are more troublesome in this regard than are rooms with lower ceilings. Architects have worked out no fast and safe rule which, if followed, will insure the best acoustic conditions. Since steel lath has been introduced for plastering and concrete construction is becoming more common, it seems that troublesome echoes are more frequent than ever before, and every precaution should be taken to deaden the walls in school buildings to prevent this grave annoyance.

Nevertheless, it is necessary to make a classroom sufficiently high to insure the proper placing of windows, adequate area of glass surface, and the conditions necessary for suitable ventilation.

Having considered these points even briefly, it seems that we shall not err to any great degree if we recommend that a standard classroom for the public elementary schools of our country should be 30 feet long, 22 feet wide, and 12 feet high from finished floor to finished ceiling.

Naturally where the area of glass surface required to light the room will be more than one-sixth of the floor surface, and especially where a ratio of 1 to 4 is needed, windows will have to be spaced carefully. The decision, therefore, as to the exact height of a classroom ought to depend somewhat on local conditions with reference to the source and quantity of light generally available.

One of the objections which will be urged against making the ceilings of our classrooms 12 feet in the clear is this: It will deprive