The vat being in a proper state, the cross suspended, and thirty ells of cloth ready, or scoured wool in proportion, designed for black, by dyeing it of a blue grey; and having passed and repassed the cloth through the liquor for a full half-hour, it is to be wound round the winch, and thrown off into the barrow, and aired by the listings to change the green to blue. After this, a second piece may be dyed by the same process. Having made this overture, or _first stirring_, as it is also called, the vat must be stirred afresh, adding lime; but not so much as to destroy the proper smell and feel. If the vat be in a good state, on the first day, it may be stirred three or four times; but it must not be overworked, particularly on the second day. _Concerning the colours to be obtained to the best possible advantage from a fresh vat on the first day_,—the first is for _black_, the next for _royal blue_, and the third a _brown green_. On the _second_ day, _violet_, _purple_, and _Turkey blues_ in the last stirring. On the _third_ day, if the liquor be too much diminished, it must be filled up with hot water. At the end of the week _light blues_ may be done, and on Saturday night add rather more lime, to preserve the vat till Monday morning. On Monday morning add more indigo, and stir the paste; keep the vat liquor at a proper distance from the top. Cover it for two hours; then put in a pattern, and in an hour take it out; add lime according to the green shade of the pattern, and in an hour or two, if your vat has not suffered, you may begin working it afresh. To keep the cloth, &c. from the sediment, there is always let down into the vat, before the work is begun, an iron circle, with cords fastened from the circumference to the centre. _On the putrefaction of the woad vat._ Whatever be the cause, most certain it is, that the woad vat, even when prepared in the most careful and scientific manner, is soon disposed, _if not used_, to go into the putrid fermentation; of this we may be satisfied, when it smells like rotten eggs, as stated above. The loss of a woad vat to dyers is extremely serious, both from the quantity of woad, as well as of indigo, which it contains: these articles being always expensive. The woad vat being worked by heat directly applied from an open fire, (the old method of heating it,) was much more liable to be lost than if it remained cold, or was worked _continually_, as it usually now is in _London_; added to which, the more equable application of heat by _steam_, there is not now the danger which there was in cessation, at uncertain times, and in uncertain states of the vat, as to richness or poorness of woad or of indigo.