- 4 pieces 1 inch by 11½ inches by 2 feet rough (ends of sand and stone boxes).
- 2 pieces 1 inch by 11½ inches by 4 feet rough (sides of sand box).
- 2 pieces 1 inch by 11½ inches by 6 feet rough (sides of stone box).
Note: The two pieces 4 feet long and the two pieces 6 feet long have an extra foot in length at each end to be made into a handle, as shown in [Fig. 3.]
For a 1: 2½: 5 mixture, you require the following sized lumber:
- 4 pieces 1 inch by 11½ inches by 2 feet (ends of sand and stone boxes).
- 2 pieces 1 inch by 11½ inches by 4 feet 6 inches (sides of sand box).
- 2 pieces 1 inch by 11½ inches by 7 feet (sides of stone box).
Note: The two pieces 4 feet 6 inches long and the two pieces 7 feet long have an extra foot in length at each end to be made into a handle, as shown in [Fig. 3.]
To illustrate the use of the measuring box, let us once more assume that a 1: 2: 4 mixture is required, and that the amount of finished concrete needed is 8½ cubic feet. By referring to the [table on page 11] it will be noted that two bags of cement are required, also 3¾ cubic feet of sand and 7½ cubic feet of stone or gravel. Under “size of measuring box” it is found that the sand should just fill a box 2 feet by 2 feet by 11½ inches, and that the stone should fill a box 2 feet by 4 feet by 11½ inches. Lay the sand box, or frame, on the mixing platform and fill it. Then raise the box. Empty two bags of cement on the sand and mix as described under “[Mixing],” see pages 14-22. Even off the mixture thus obtained with your shovel, place the stone measuring box on top of the mixture and fill it. Raise the measuring box—and you have the correct amount of stone all ready to be mixed with the cement and sand. It is important to measure both the sand and stone loose in the box—never “pack” them.
For purposes of explanation, size of mixture will be referred to as a “batch” of so many bags of cement. Thus, a “two-bag batch of concrete” would mean one requiring two bags of cement, with the sand and stone proportioned accordingly, as shown above.
For a “four-bag batch of concrete” it would be necessary to multiply the amount of stone and gravel by 2, also multiplying the cubic contents of the measuring box by 2, and using four bags of cement instead of two.
The [table previously referred to] also shows the amount of water for different sized batches, but it is to be noted that the quantity of this ingredient is only approximated. Use the amount indicated in the table for the first batch, and if it proves too wet for the use desired, reduce the amount of water; if too dry, increase the amount of water. Always use a bucket in measuring the amount of water, as this secures uniform results.