The simplest way to determine the weight of a large body is to measure its volume and then multiply that by the weight of a unit volume of the substance. The weight of a unit volume of any substance is called its density.

Fig. 5. Inside Calipers. For measuring inside bore diameters.

Fig. 5. Inside Calipers. For measuring inside bore diameters.

Fig.6.   Outside Calipers. For measuring outside diameters.

Fig.6. - Outside Calipers. For measuring outside diameters.

Fig. 7.   Weighing Scales.

Fig. 7. - Weighing Scales.

These scales will weigh any body not more than 1 lb. in weight. Its scale is graduated in ten-thousandths of a pound. Such scales are used for weighing small articles, screws, samples of paper, etc. The weights are in front of the scales. The object to be weighed is placed in the pan.

The density of various substances has been compiled and reference tables have been prepared. The rule for determining the density of any substance may be written:

Density = Mass or weight in pounds / Volume in cubic feet

It follows therefore that:

Weight = Density X Volume

Volume = Weight / Density