However impressive the final form of the Cholula pyramid was, it recedes against the magnificent achievement of the Pyramids of the Sun and the Moon which were erected in a short span of time, in possibly less than half a century. It turns out that in this, and many other respects, they are the representatives of an Amerindian pyramid age which closely approximates the Fourth Dynasty in Egypt. The parallel becomes even closer when we regard the amount of labour involved at Teotihuacan against the cultural and economic background of the Valley of Mexico 2,000 years ago.
The total amount of material to be quarried, carried to the site, lifted up to an average height of 20 m., distributed and rammed in, was roughly 30 million tons. Most of the pyramidal fill is 40 Representations of the butterfly god of Teotihuacan on ceramics. The top figure shows him associated with the rain god Tlaloc (after Sijoumi) excavated subsoil, but an appreciable amount of quarried stone and prepared adobe was also required. Some of this had to be obtained from a distance of at least several kilometres. The implements available were wooden and stone tools. There is no record of sledges being used for transport, beasts of burden did not exist, and the wheel had not been invented at the time of the Conquest, 1,500 years later. All loads had to be carried, and in addition to the workers actually engaged in the building process others were needed to supply the whole force with food and water. Although the population was certainly accustomed for generations to the local conditions, it has to be remembered that the diminished amount of oxygen at an altitude of 6,000 feet will have had an effect on the efficiency of heavy labour.
Taking all these factors into account we might assume an average of 75 kg. per man to be placed per day. This estimate, of course, covers all the varied activities required by the project. We assume further that the workers were, as in Egypt, agricultural labourers and that, in order to maintain food production, they could spare, at best, a hundred days per annum on pyramid construction. For a building period of thirty years this leads to a labour force of about 15,000 men.
It has to be emphasised that, just as in our estimate of work in Egypt, the number cannot be expected to be correct except within an order of magnitude. However, it is quite clear that the project could not have been undertaken as a secondary activity. In other words, a large proportion of the population must have been involved in it for a very considerable time. Again, as in Egypt, the very large pyramids occur early in the development of civilisation.
We are further aided in our assessment of the conditions under which the pyramids were built by the figurines that were found embedded in the building material in large numbers. These artefacts are helpful in determining the period at which the work was done and they agree with the available carbon dates. The figurines in the Pyramid of the Sun all belong to the so-called Tzacually period which came to an end at about 100 BC. Even more important is the fact that different villages used slightly different styles for their figurines and pottery and the distribution of styles found in the pyramid material indicates that the builders came from a fairly widespread area in the Valley.