There were two values to the Braza or Fathom in old Spanish measures, one was the equivalent of 65·749 English inches, and the other and more ancient was the equivalent of 66·768 English inches. In computing the following measurements I have used the latter scale:— Spanish. English. 1 foot = 11·128 inches. 3 feet = 1 vara = 33·384 „ = 2·782 feet. 2 varas = 1 Braza = 66·768 „ = 5·564 „ The Pace is reckoned as equal to 2·5 English feet and the Ell mentioned by Tezozomoc as the Flemish Ell = 27·97 English inches or 2·33 English feet. There is a general agreement that the Teocalli was a solid quadrangular edifice in the form of a truncated step pyramid. The dimensions of the Ground plan are given as follows:— Spanish Measure. English feet. ANONIMO 150 × 120 paces = 375 × 300 TORQUEMADA 360 × 360 feet = 333·84 × 333·84 GOMARA 50 × 50 Brazas = 278·2 × 278·2 TEZOZOMOC 125 Ells (one side) = 291·248 BERNAL DÍAZ = six large Solares measuring 150 × 150 = 341 × 341 feet each, which would give a square of about IXLILXOCHITL 80 Brazas = 445[6] Motolinea says the Teocalli at Tenayoca measured 40 × =222·56 × 40 Brazas 222·56 The measurements are rather vague. The Anonymous Conqueror’s measurements may refer to the Teocalli at Tlatelolco and the length may have included the Apetlac or forecourt. Torquemada may be suspected of exaggeration. Tezozomoc was not an eye-witness and Bernal Díaz’s estimate of six large Solares is only an approximation. In Tracing A_{2} I have taken 300 × 300 English feet as the measurement of the base of the Teocalli. Orientation of the Great Teocalli. SAHAGUN Facing the West. TORQUEMADA Its back to the East, “_which is the practice the large Temples ought to follow_.” MOTOLINEA The ascent and steps are on the West side. TEZOZOMOC The principal face looked South. IXTLILXOCHITL Facing the West. I think the evidence of Sahagun, Torquemada, Motolinia, and Ixtlilxochitl must be accepted as outweighing that of Tezozomoc, who also says that the pyramidal foundation was ascended by steps on three sides, a statement that is not supported by any other authority and which received no confirmation from the description of the attack on the Teocalli as given by Cortés and Bernal Díaz. THE STAIRWAY.