After tobacco the most important product of the Cumanacoa valley is indigo, whose intense color makes it the equal of Guatemalan indigo. All the indigo factories that we visited are constructed along the same principles. Two vats, where the plants 'rot', are placed together. Each one measures 15 feet square and 2. feet deep. From these upper vats the liquid passes into beaters where the water-mill is placed. The axle-tree of the great wheel crosses the two beaters. It is nailed with ladles, fixed to long handles, for the beating. From another percolating vat the coloured starch passes to the drying-boxes, spread on planks of Brazil-wood on small wheels so that they can be pushed under a roof in case of sudden rain. These sloping and low roofs give the drying-boxes the appearance of hothouses from a distance. In the Cumanacoa valley the fermentation of the plant takes place amazingly quickly; usually it does not take longer than four or five hours. This can be attributed to the humidity and the absence of sun during the plant's development.