Height of Ceilings.-The shop may be either an independent unit or a wing of a trade school or high school. The height of ceilings will depend upon whether the unit is one or more stories in height. In either case, however, the ceiling height should be at least 13 feet, and preferably 15 to 20 feet.

Arrangement of Supporting Columns.--The arrangement of supporting columns depends upon the number of floors above the shop and

the arrangement of partitions on the upper floors. If the auto shop is located in a one-story building, the supporting columns should be in the center line of the shop. If the unit is two or more stories high, and the hallway on the upper floor is in the center of the building, it will probably be necessary to have two rows of supporting columns directly under the hallway partitions. However, since the location of supporting columns will be determined by the archi

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tect, it seems hardly necessary to give a detailed discussion of the matter here.

Windows. One of the most important factors to be considered in planning a shop building is the lighting. Skylights are often used and have many advantages, but since in all probability the auto shop will be located on the first floor of a two-story building, the windows should be placed so as to obtain adequate lateral lighting.

The proper lighting for school shops is the modern factory lighting plan in which the walls consist of a series of supporting columns with the intervening spaces filled in with glass set in wood or steel window frames. On the east, south, and west sides, which are exposed to the direct rays of the sun, windows should be glazed with diffusing glass. If the auto-shop unit is in a wing of a building, the type, size, and shape of windows should harmonize with the re

mainder of the building. Double-hung windows are preferable for first-floor shops on account of the ease with which this type of windows may be screened or barred. The use of factory sashes which swing out makes it necessary to use elaborate and expensive window screens and guards which are not as strong and durable as a flat screen. Double-hung windows in units of three have been found to be very satisfactory. The muntins and bars may be arranged for large or small glass lights to harmonize with the architectural treatment of the rest of the building.

FIG. 5.-Automobile shop, El Paso (Tex.) Vocational School (Note overhead trolley for chain hoist; also note that windows swing inward to allow the use of flat screens or guards on outside of windows)

The amount and type of space for teaching related subjects will depend upon the method used in giving the technical instruction. In some automotive schools and courses all directly related technical knowledge is taught in the shop at the time it is needed on the job. For example, if a student were being taught to rebore a cylinder block and to fit pistons, he would be given instruction in reading micrometer calipers at the time that it became necessary for him to use the calipers to set the blades on his reboring tool. In other words, according to this precedure, the giving of technical knowledge is incidental to the training in manipulative skill. When this method of teaching related subjects is used the only additional space required for related-subjects instruction is a place for a blackboard

for the showing and displaying of charts and floor and bench space for models and sectionized parts.

In planning the shop layouts given in this bulletin due consideration has been given to the requirements of floor and bench space for models and sectionalized parts as commonly used in teaching related technical subjects by the method described in the foregoing paragraph.

A second method of teaching related subjects is to have a space provided with blackboard, chairs, and the like, where the class can assemble and receive individual or group instruction. This space may be either a part of the shop or a separate room. If this space is a part of the shop it should be partitioned off in order to keep out noise and to make possible the regulation of the temperature and light to conform to the needs and working conditions of related subjects instruction.

There are some advantages advantages in having the related subjects room adjacent to the shop, but since ground-floor space is often difficult to obtain it would, in many cases, be better to use a second-floor room for related subjects than to cut down the ground-floor space available for shops.

Since the technical knowledge related to the auto mechanics trade consists largely of science, mathematics, and drawing, one room could be equipped for giving instruction in all three subjects. No

formal mechanical drawing is needed by the auto mechanic, therefore it would not be necessary to provide a room equipped with regular drawing tables and complete mechanical drawing equip

ment.

Experience has shown that a room equipped with flat-top tables, seating from two to four students each, provides the most satisfactory equipment for teaching related mathematics, drawing, and