Length Measuring Instruments. In antiquity, the human being used tools of identify the dimensions of the objects places. At fist thhey used own body for that purpose, for example: the step, the span, the brace, the inch, the foot, among, others. Over time other instruments were used, such as the ruler, the tape measure, from which we can trace its origins from ancient Rome where the Romans used to use leather belts marked with conventional measuring units for that time and place.