8 THE PRIMEVAL MONUMENTS OF PERU. 
The stones forming the dome are not only cut on accurate 
radii, but the curve of the dome is preserved in each, and 
they are furthermore so eut that their push or plunge is in- 
ward towards the centre of the structure, thereby tending to 
give it compactness and consequent strength. There are 
many other interesting architectural features connected with 
these remains of Sillustani, the enumeration of which is 
not necessary in order to illustrate the particular question 
before us.* 
Some of the chulpas of Sillustani have double vaults or 
chambers, one above the other, and 
others have a double row of niches, in 
a single chamber, with a cist, carefully 
walled up, sunk in the earth below. 
There are a few built of rough stones 
plastered and stuccoed over, and paint- 
ed, with inner chambers also stuccoed. 
Now, in all these varieties of the 
burial monument called the chulpa, 
from the rude pile of rough stones at 
Acora, so much resembling the Euro- 
L. pean cromlech, through every variety 
Section of a (fig. 4). 
towers of Sillustani we discover com- 
mon features, a common design, and many evidences that 
all were equally the work of the same people. If so, do 
the ruder monuments mark an earlier and possibly very 
remote period in the history of that people? And do the 
various stages of development which we observe in this class 
of monuments, correspond with like stages in the develop- 
ment of their builders? Or did they build -the rough tomb 
*For Dierk of comparison, I introduce a reduction from a photograph, of a ioni 
led P among the ruins of Alatri, Italy (Fig. 7). The 
sa ce "pieta he style and wo rkmanship of the Sillustani monuments and sie 
of — is voee hash that the stones of the former are much the largest, and are 
cut fitted witl t muc 'h greater accu maey: In n no 
of st 
h 1 
g of perfection i& was by the ancients of 
Peru. 
