41. Your children's teeth (14:24)

Date:
1945
Summary:
Discusses the importance of prenatal care of mothers and the eating of proper foods in helping children to develop good teeth. The structure of teeth, the progress of tooth formation, and the process of decay are explained by means of diagrams.

42. Quadrilaterals (12:51)

Date:
1944
Summary:
Illustrates and explains the chief properties of the important quadrilaterals such as the parallelogram, rectangle, rhombus, square, trapezoid, and trapezium.

43. Radio dynamics (04:20)

Date:
1942
Summary:
Visualizes Color-keyed moods, recurrent themes, contrapuntal melodies, and various rhythmic patterns through the animation of Oskar Fischinger. Presents an interplay of shapes, Colors, and movement in GasparColor.

44. Defending the city's health (11:14)

Date:
1941
Summary:
Modern community hygiene controls are presented. How the death rate from communicable diseases has been reduced through scientific advances and social controls. The effective functioning of a public health department.

45. Drilling and tapping cast steel (18:58)

Date:
1941
Summary:
Technique of drilling and tapping blind holes in cast steel on a radial drill. A drill jig with loose bushings is used for locating the holes. Setting up the work on the table of the machine, setting the jig on the piece to the layout lines. Calculating the size of the tap drill and the method used when setting the machine to drill a number of holes to the same depth. A wizard drill chuck is used in the drilling operation, and a standard friction chuck for holding the tap. The action of a tap in a hole is shown in animation and the reason why a tap binds in the hole and must be reversed frequently when tapping in tough metals.

46. Distance races (10:04)

Date:
1938
Main contributors:
Erpi Classroom Films, Lawson Robertson, Dean Cromwell, Brutus Hamilton, Harold A. Bruce, Amateur Athletic Union of the United States
Summary:
Includes races from 1,000 to 10,000 meters and steeplechase. Style of distance runner contrasted vividly with that of dash man. Differences in typical physiques. Steeplechase portrays various methods employed by participants in clearing barriers. An instructional sound film.