Manufacture. 67 



of having the whole equally covered with water 

 and thereby aid the fermentation, which is enough. 

 However, you should always have about six inches 

 clear from the top of the steeper, to allow room for 

 the rising of the water undergoing fermentation, other- 

 wise during that process it will run over and waste. 



Fifth. The night being moderately fair, the plant 

 good and not inundated before, in nine or ten hours 

 it will generally be ready to draw off. Now, see 

 that your people are ready, and have the beaters 

 thoroughly washed out before use. Those who aim 

 at making extraordinarily fine blue, steep a much 

 less time, and generally lose a considerable portion 

 of their produce, and not unfrequently make their 

 indigo of too light a colour for general use. As 

 the fermentation goes on, air bubbles rise upon the 

 surface of the water, until at length the vat has the 

 appearance of a broccoli head ; now watch care- 

 fully the ebullition of the vat, and the moment it 

 begins to subside and sink down in the steeper, let 

 off the liquid, and you will generally be safe. If it 

 runs out a bright straw-colour, tinged with green, the 

 indigo will be fine ; if a strong madeira colour, good ; 

 if of a very pale straw-green, violet, and dirty-red, 

 bad (coppery.) The first indicates good steeping ; the 

 second, a little too long; the third, not enough . 

 and the last, overdone, This will be your guidance, 



