These are only conjectures, but it cannot be supposed that this knowledge of architecture and of sculpture arose as suddenly as it disappeared, and sprang into existence as the outcome of the natural capacity of the Indian mind. The problem is interesting and attractive. It is one that is exceedingly difficult to solve.
There are certain differences in the methods of construction of Palenque and Uxmal which have to be analyzed. The walls at Palenque are composed of compact masses of stones and mortar covered with thick layers of cement. At Uxmal no coatings of cement are used and the walls are faced with well-worked masonry. At Palenque there are great numbers of human figures either formed of thick stucco, or graven upon slabs of stone. At Uxmal there are no human figures, no delineations of caciques, priests, or captive victims. The principle of ornamentation is different.
Judging from the condition and appearance of the buildings it is clear that Uxmal must be more modern than Palenque, and this is particularly noticeable upon an examination of the Casa del Gobernador and the Casa de las Monjas. The influences of the tropical climate (Uxmal is half a degree south of the twenty-first parallel) are such as would be expected to act injuriously upon exposed limestone sculptures, for between May and November the rains are heavy and continuous. But the façades of these structures seem to have been very little affected by the weather.
In forming opinions respecting the antiquity of ruins, it is perhaps injudicious to give much weight to considerations based upon appearance or state of dilapidation, but in the instance of Uxmal there are circumstances which make it impossible to admit that it belongs to a period more than very few centuries earlier than the arrival of the Spaniards. Thus the preservation of the wooden lintels over the doorways in the Casa de las Monjas must be taken into consideration, when any attempts are made to estimate the age of that building. They have had to bear considerable pressure, for there are heavy masses of concrete and masonry to be supported.
With regard to this subject, it is necessary to draw attention to the size and construction of one of the principal rooms which I measured, and it will be understood how the architects were limited or restricted in their actions, and to what extent the employment of wood was found to be requisite.
It was a narrow chamber twenty feet four inches long, twelve feet wide, and about twenty-three feet high. The height of the entrance was eight feet, the width six feet seven inches. The interior walls were perpendicular up to nine feet three inches from the ground, and then curved inwards until they approached within one foot of each other. They were capped by broad flat stone slabs. The curvature of the walls was correctly formed, and a considerable gain in space was thereby obtained. It was evident that the Indians were advancing towards a knowledge of the round arch and keystone. This form of rounding the inner roof was not however adopted in all the rooms of the nunnery. Many of them still retained the straight lines of converging walls, as at Palenque. The manner in which the advance in construction had been reached was simple and yet ingenious.
I measured a room in another part of the quadrangle which had different dimensions, and was more in accordance with the earlier system of building. It was twenty-two feet long and ten feet five inches wide. The height of the perpendicular portion of the walls was eight feet three inches, and the length of the upper slope to the cap-stone was eight feet nine inches. The total height of the room about sixteen feet. The doorway was a little over seven feet high and the width was five feet eight inches. The dimensions of the chambers round the quadrangle varied, but the instances I have given represent their average sizes. There were two lintels over each doorway, for the width of each piece of timber was not sufficient to occupy the full depth of the wall. In the first-mentioned chamber they were each nine feet five inches long, one foot wide and eight inches deep, and had a bearing upon each wall of one foot five inches. In this and other openings the inner lintel rested in its place a little lower than the outer one. The object of this singular method of placing these supports was not apparent. The lintels were externally in perfect condition, and were without any signs of decay.
The main mass of the Uxmal walls is composed of rubble limestones, made into a strong compact substance, by the plentiful use of good binding mortar. Each facing stone was made into a triangular shape, and the point or apex seems to have been pushed or fitted into its place, and there firmly secured by mortar. This method of applying the masonry was adopted not only with the plain smooth blocks of square stone used for facing the lower portions of the buildings, but also with all the sculptured portions of the walls. The blocks fit closely together in their places so accurately and with such careful finish that the joints or edges can scarcely be distinguished. It is thus made evident that the stone-masons who built Uxmal must have been men capable of performing their work with skill. The architect must have possessed a competent knowledge of the preparation of a plan or design, and the masons, in separately executing their part of the sculpture, must have been able to follow the design with an exactness that is almost mathematical.
There have been many theories respecting the methods that may have been practised by the Indians in executing their carvings upon stone, but no knowledge has been obtained which throws sufficient light upon the subject.[92] No attention has however been directed to the artisan qualities of the workmen who shaped and fitted the lintels, which however prove that the workers in wood were as skilful as the masons. The lintels were made of wood harder than mahogany. I examined many of them with the utmost care, and could not detect the slightest mark or dent. It is doubtful whether a good carpenters plane could have given them a smoother surface. The zapote trees out of which they were formed, must have been fashioned into broad baulks of timber, and afterwards squared and divided into the required lengths. The face of the timber was levelled and smoothed, and the corners or angles were sharply defined. All this work had to be done, as far as is known, with stone implements.
