The Educational screen (c1922-c1956])

April, 1940 Page 167 of the three systems of circles. The accompanving sketch indicates how three coat hangers or hoops placed at right angles, and with a smaller circle parallel with the horizon, portray the chief circles of the horizon system. The labels can conveniently be attached with scotch ta])e. now universally used in schools. This construction work provides sensory experience of great value to the pupils. The Inverse Squares Model The "Inverse Squares l^w" is fundamental to much of the physical science work. Newton's Law of Uni- versal Gravitation states " the attrac- Inverse Squares illustration tion between the bodies varies inversely as the square of the distance between their centers." The inverse law holds for the intensit)' of illumination, etc. A mo<lel can easily be made of wire, as shown in the ac- companying illustration, with the squares properly placed t(i produce areas in the ratio of 1. 4, and 16. Pupils can readily make such a model of wire. A fun- damental thing about the use of these models is that the three-dimension relationship is more easilv under- stood and gives a clearer insight than can be gained from the blackboard drawing of the textbook illustra- tion. Comparative Size Model Abstract numbers in terms of thousands and millions of miles often convey very little meaning to children. If comparisons are made these same facts may take on worth \\hile meaning. The pupils can make compara- tive size models for: the planets; some of the stars; the moon and the earth. The ten-cent store abounds in glass headed pins, beads, balls, and marbles of various sizes. After some calcula- tions with the diameters of the various heavenly bodies, it would be possible to secure some of the inexpensive materials to be used in constructing the comparative size models mentioned above. This work should result in meaningful understandings of the size relationships. Altitude-Latitude Calculator Since the axis of the earth points toward the north star, if one were at the north pole the north star would be directly overhead, or at an angle of 90° with the surface of the earth. If one were at the equator and pointed towards the north star, he would have to point parallel with the axis of the earth at an angle of 0°. Hence as one goes north from the equator he must devate his sights one degree for every degree traveled northward to be able to see the north star. This brings the fundamental law, "The altitude of the pole star equals the latitude of the place." Pupils can construct "alti- tude-latitude calculators" by tacking or bolting two // /# Science and Agriculture ...one of 25 Instructional Sound Films on Human Geography and Social Science What it does: Shows interdependence of sci- ence and agriculture in modern life. Traces soy bean from China through its culture and use in U. S. for soil conservation. De- scribes uses of soy bean by-products in home and industry. Scope of use: From 4th grade through adult level. (1) In Geography and Elementary Social Studies; (2) In Elementary and Gen- eral Science; (3) In Agriculture and Indus- trial Arts; (4) In Biology and Botany; (5) In Chemistry and Physics; (6) In Sociology and Economics; (7) In Home Economics and Vocations. For full details of the wide range of subject matter covered by Erpi's large selection of instructional sound films, send the coupon today. Instructional Sound PRIMARY GRADES . . 17 films HUMAN GEOGRAPHY and SOCIAL SCIENCE 25 films BIOLOGICAL SCIENCES Plant Life 8 films Animal Life 13 films Human Biology ... 10 films PHYSICAL SCIENCES Astronomy 4 films Geology 9 films Films for use in: PHYSICAL SCIENCES (Cont.) Physics 10 films Chemistry 6 film$ MUSIC SERIES 5 films ARTS AND CRAFTS . . 4 films ATHLETIC SERIES ... 4 films CHILD PSYCHOLOGY . 13 films VOCATIONAL GUIDANCE 2 films TEACHER TRAINING . 6 films Frpi Classroom Films Inc. ERPI CLASSROOM FILMS INC. !■.»-*-*» 35-11 Thirty-fifth Avenue. Long Island City, N. Y. Gentlemen: Please send me your complete descriptive catalog and your .o|iecial Integration Chart which shows graphically how each film can be used in a number of dif- ferent course*. Name Address .