eter was used, having one set near the sustaining bars 

 in the lower portion of the chamber, the other near 

 the apex of its dome. The file and the damper were 

 so worked as to have the index hands of this double 

 instrument coincide; this was only used in acquiring 

 a perfect knowledge of the manner of working the 

 furnace. In the first annealing of fine brass wire in 

 the annular pots, two cupels were placed side by side, 

 with a button of fusible alloy on each, one that would 

 melt at a temperature sufficient to thoroughly anneal 

 the wire without danger of melting it, the other to 

 melt at the danger point, which the operator had to 

 be careful not to reach. Careful practice soon taught 

 how to operate with safety, trusting to eye sight right 

 through the peep-hole in the door, and judging by 

 the color of the annealing pot, which, when it arrived 

 at the proper heat, the dampers were closed and time 

 given for the heat to penetrate the entire mass of 

 encased wire; the average time required to anneal a 

 pot was about one hour. One man with a long, 

 forked, iron lever, suspended by a chain to a crane, 

 would with ease withdraw the hot pot and replace it 

 with a cold one. 



I have been thus particular in describing the early 

 practice of my grandfather in annealing both iron 

 and brass wire, believing, as I do, that the credit of 

 the experiments that led to the use of close iron anneal- 

 ing pots is due to him, and that England is indebted 

 to America for an advance that not only improved 

 the quality oftheir card tooth wire, but made con- 

 siderable saving from the waste of oxidation and its 

 removal by the acid pickling process. The principal 

 proprietor of the English works I alluded to in my 

 last paper 1 -'° told me that he had served his apprentice- 

 ship at them. He would not give the exact date of 

 their commencing the use of the close annular anneal- 

 ing pots, but he was confident that it was prior to i 780, 

 or about that period, for they then commenced fur- 

 nishing the firm of N. & D. Sellers with card wire, 

 they having given up the iron wiredrawing branch of 

 their business. That, on the receipt of the first order 

 for card wire, and fine numbers of iron wire for 

 weaving, Mr. Xathan Sellers made it an indispensable 

 condition that no acid should be used after the wire 

 had been reduced to No. 14, that all after annealings 

 required should be done in close pots, or annealing 

 kettles, as he called them, to exclude the air, and to 



120 Probably Mathews of London. The "last paper" forms 

 the first part of this chapter. 



enable them to do this he sent them sketches of his 

 furnace and pots, and gave an account of the experi- 

 ments he had tried that led to their adoption. 



At the time of my visit this firm had been the agents 

 of and regular correspondents of N. & D. Sellers and 

 their successors for over 60 years. They had carefully 

 preserved the old sketches, which were shown to me, 

 and which I at once identified as the work of my 

 grandfather. They unfortunately were not dated, 

 though reference to some of the early correspondence 

 fixed the date about as above stated. The advantages 

 of annealing the finer qualities of iron wire excluded 

 from the air, was considered of such importance to 

 the concern that for a quarter of a century that portion 

 of their work was done secretly by a member of the 

 firm and one or two confidential workmen. From the 

 most reliable information I could obtain it was not 

 until the beginning of the present century that other 

 wire works adopted the pot or retort system of anneal- 

 ing, and then it was introduced into England by 

 French workmen from the manufactory of Messrs. 

 Mouchel, of the department of L'Orne, France. 



What struck me as most extraordinary was that a 

 concern who for so long a period had successfully 

 annealed their iron wire for card cloth and fine steel 

 wires for musical instruments, had so utterly failed in 

 every attempt to anneal fine brass wire. Thev said 

 the lower coils in the pots were certain to melt and 

 run together, when the upper ones would not be suffi- 

 ciently annealed to draw well. 



After having their furnace remodeled, I admit to 

 having found considerable difficulty in getting up and 

 maintaining a perfectly uniform heat with coke as the 

 fuel, it requiring a different management of both the 

 lower draft and the conical soapstone damper; but 

 after a little practice I made the venture successfully 

 with a pot charged with brass wire of a number fine 

 enough to weave into vellum wire of 80 meshes to the 

 inch. 



As late as 1832 some of the English wire mills were 

 still annealing their coarse wires in the flames of a 

 reverberatory furnace, and wasting stock and injuring 

 quality by severe vitriol cleaning, and others that 

 were using retorts or pots did not charge them to 

 exclude the air as effectively as it should have been 

 done for saving in the vitriol process. Two extensive 

 card-wire mills that I visited were exercising the 

 greatest possible care in charging their pots and 

 luting them, bringing the wire out in condition for 

 the wire plates without the use of acids to an in- 

 jurious extent. [34] 



94 



