On my beat again, and close to Limehouse Church, its termination, I found myself near to certain 'Lead-Mills.' Struck by the name, which was fresh in my memory, and finding, on inquiry, that these same lead-mills were identified with those same lead-mills of which I made mention when I first visited the East London Children's Hospital and its neighbourhood as Uncommercial Traveller, I resolved to have a look at them.
Received by two very intelligent gentlemen, brothers, and partners with their father in the concern, and who testified every desire to show their works to me freely, I went over the lead-mills. The purport of such works is the conversion of pig-lead into white- lead. This conversion is brought about by the slow and gradual effecting of certain successive chemical changes in the lead itself. The processes are picturesque and interesting, - the most so, being the burying of the lead, at a certain stage of preparation, in pots, each pot containing a certain quantity of acid besides, and all the pots being buried in vast numbers, in layers, under tan, for some ten weeks.
Hopping up ladders, and across planks, and on elevated perches, until I was uncertain whether to liken myself to a bird or a brick- layer, I became conscious of standing on nothing particular, looking down into one of a series of large cocklofts, with the outer day peeping in through the chinks in the tiled roof above. A number of women were ascending to, and descending from, this cockloft, each carrying on the upward journey a pot of prepared lead and acid, for deposition under the smoking tan. When one layer of pots was completely filled, it was carefully covered in with planks, and those were carefully covered with tan again, and then another layer of pots was begun above; sufficient means of ventilation being preserved through wooden tubes. Going down into the cockloft then filling, I found the heat of the tan to be surprisingly great, and also the odour of the lead and acid to be not absolutely exquisite, though I believe not noxious at that stage. In other cocklofts, where the pots were being exhumed, the heat of the steaming tan was much greater, and the smell was penetrating and peculiar. There were cocklofts in all stages; full and empty, half filled and half emptied; strong, active women were clambering about them busily; and the whole thing had rather the air of the upper part of the house of some immensely rich old Turk, whose faithful seraglio were hiding his money because the sultan or the pasha was coming.