MORGAN. | TRIANGULAR CEILING OF STONE. 963 
the partition walls are found in place. The proof of the comparatively 
modern date of these structures is conclusive from these facts alone. 
It will be observed that there are six single apartments in the building 
on the right of the “House of Nuns” which have no connection with the 
remaining rooms of the building, and that the others are in pairs, a back 
room connecting with the one in front, and neither with any others. It 
seems to show very plainly, in the plan of the house itself, that it was de- 
signed to be oceupied by distinct groups composed of related families, each 
group a large household by itself. If the communal principle in living 
existed in fact among them, its expression in the interior arrangement of the 
house, and in this form, might have been expected. This striking and sig- 
nificant feature runs through all the structures, in these areas, of which 
ground-plans have been obtained. 
5) 
sections across the vault of a chamber in the place of joists, and, so far as 
The triangular ceiling, in effect, is an attempt to extend the lintel in 
the writer is aware, the only attempt ever made by any barbarous people 
to form a ceiling of stone over ordinary residence rooms. In a wall and 
ceiling formed in this manner, and carried up several feet above the apex 
of the triangular arch, there would be no lateral thrust outward of the 
masonry. 
It should be stated that there are neither fire-place, chimneys, nor win- 
dows in any of these houses; neither have any been found, so far as the 
writer is aware, in any ancient structure in Yucatan or Central America. 
Fires were not needed for warmth; but since they were for cooking, it shows 
very plainly that no cooking was done within these houses. A presump- 
tion at once arises that their inmates prepared their food in the open court, 
or on the middle terrace, by household groups, making a common stock of 
their provisions, and dividing from the earthen cauldron, like the Iroquois. 
The communistic character of these houses is shown by their great size, and 
by the separation of the rooms, generally in pairs, having no connection 
with the remainder of the house. Each pair of rooms would accommodate 
several married pairs with their children; and so would each single apart- 
ment, according to the mode of life of the Village Indians. Moreover, 
communism in living appears to have been a law of man’s condition both 
