Abstract: A concrete crack control system is provided. The system comprises a vane or angle projecting from a wall, such as a pedestal or column or other wall surfaces against which a concrete floor or slab is poured. After the concrete has set to firm consistency, a saw cut is provided of a substantial depth in line with the projecting vane. The exposed saw cut may be filled with conventional filler, such as grout or the like. Any tendency of the floor to crack upon aging will be along the line of the vane and saw cut, thereby preventing crack damage to the floor.

Abstract: A metric system teaching and measuring device. The device is in the form of a tubular meter stick having an internal cross sectional area of ten square centimeters producing the volume of one liter for one meter length of the stick. An attachable base provides means for closing the bottom of the stick to form a graduate cylinder. Markings provided through a one meter ruler having centimeter and millimeter markings enable the reading of volume corresponding to centiliters and milliliters respectively. In the graduate form the device may contain a 1 kilogram mass of water with each cubic centimeter or milliliter of water corresponding to 1 gram. By the use of a float the device can be used to determine the mass (or weight) of small objects heavier than the displaced fluid such as water when the object is placed inside the float using known mass of the float as tare.