Figure 17. — John White's 

 screw-cutting lathe, about 1817. 

 The chasing tool is attached to the 

 long wooden handle which rests 

 on the operator's shoulder. The 

 advance of the tool along the 

 workpiece is initiated by the 

 "screw-guide," located at the 

 right-hand end of the workpiece. 

 However, the operator had to 

 possess skill as well as brawn in 

 order to chase a uniform thread. 

 The model shown here was built 

 for the U.S. National Museum 

 from the description given in the 

 present chapter. Smithsonian 

 photo. 



boring was followed by Patrick Lyon, the then cele- 

 brated builder of fire engines in Philadelphia, for 

 boring his brass engine cylinders. 



As to how long this primitive process of press screw 

 making was carried on after the time I am alluding 

 to, I have no way of knowing with certainty. I have 

 an impression that Mr. White died before 1821. 



I recollect a curious incident connected with these 

 screws: The house of which my grandfather was head 

 received through the Spanish Consul resident in Phil- 

 adelphia a letter of inquiries as to the cost of a large 

 number of wrought iron screws, a peculiarity of which 

 was they were to be forged solid, then bored out, 

 leaving a certain thickness of shell, the hole closed by 

 a well fitted plug secured by a screw tapped half in 

 the shell and half in the plug. Other peculiarities 

 were explained by the Consul as a necessity to secure 

 lightness, as they had to be transported long distances 

 either on ass or llama backs. The order came, the 

 screws were made, and shipped through a Philadel- 

 phia drug house having extensive commerce with 

 South America. At the same time was shipped by 

 Cadwallader and Oliver Evans machinery for a flour 

 mill. Some years afterwards, when the old United 

 States Mint on Seventh Street was being dismantled, 

 the machinery broken up and sold as old metal. I 

 noticed among the rubbish some old rusty, battered, 

 hollow screws, that reminded me of the screws made 

 by White. I stated the circumstance of that order 

 to Mr. Adam Eckfeldt, the then coiner. He smiled, 

 and said he could tell the sequel. It was like a 

 sermon of three divisions and finally: Firstly, when 

 the screws were made, from some cause mercury was 



cheaper in Philadelphia than either Spain or South 

 America. When produced, the hollow screws were 

 filled with mercury, and in that condition reached 

 the gold mines. The secondly was, after the mercury 

 was run out, the hollow body was made to take the 

 place of an ingot mould and cast full of gold, the 

 plugs returned and securely riveted, some bent and 

 broken, all badly rusted, and with other pieces of 

 machinery were safely transported to the seaboard 

 shipping port, having offered no attraction to brig- 

 ands who infested all the roads. The thirdly was, as 

 old machinery and waste metal they passed the Cus- 

 tom House and evaded a heavy export duty levied 

 on all gold shipped to any other country than Spain: 

 they also got cheap transportation and safety by 

 vessel to Philadelphia. The finally was the golden 

 harvest at the old United States Mint. They had 

 answered the purpose of the projector, had brought 

 into our country over 8150,000 that otherwise could 

 not have reached it in a direct way. They had lett 

 their maker's hands at a cost probably not exceeding 

 S30 each, and returned after their long travel by 

 water and by land, each carrying within its old. 

 battered, rusty shell over $5,000 of pure gold. Some 

 of these old screw shells should have been preserved 

 as relics of Yankee ingenuity, for it was all the work 

 of an American who had found his way to the gold 

 mines in the mountains of South America. The 

 humor of the thing was making the Spanish Consul, 

 probably an innocent party to the fraud against 

 their customs, act as a go-between in the entire 

 transaction. [14] 



35 



