10 
In speaking thus of Roberts’s inventions, I consider that I 
am only doing justice to a highly meritorious engineer, whose 
ingenious contrivances, although undoubtedly attended with 
some defects, which have led to certain of his arrangements 
being superseded by others of a more perfect character, must 
yet be admitted as having furnished some of the brightest 
examples of the mechanical genius of the present age. Mr. 
Roberts was the inventor of the first practical self-acting mule. 
Mr. Dyer is correct in attributing to the inventions of Mr. 
Smith, of Deanstone, “ much novelty and some good proper- 
ties,” and in stating that Mr. Smith’s and Mr. Roberts’s mules 
were the chief competing mules for many years. I really, 
however, cannot understand Mr. Dyer when he comes to speak 
of Mr. Potter's inventions. The patent of 1836, to which 
Mr. Dyer evidently refers, was not taken out by Messrs. John 
and James Potter, but by Mr. James Potter only ; that 
gentleman being, as I know personally, an extremely in- 
genious mechanic. Mr. Potter’s mules have had no incon- 
siderable amount of success. Mules to the amount of many 
thousands of spindles have been made and sold under Mr. 
Potter’s patents, as I know personally. A large firm of 
cotton spinners, with whom I was formerly connected, pur- 
chased and used a number of them, and I have no hesitation 
in saying that they possessed qualities which rendered them 
for some purposes preferable, on the whole , to either Roberts’s 
or Smith’s mules. Such, indeed, w T as the admitted merit of 
Mr. Potter’s invention, that on the approach of the termina- 
tion of the fourteen years for which his patent w&s originally 
granted, the Lords of the Privy Council granted a prolonga- 
tion of the patent for five years. 
I am much surprised at what Mr. Dyer says in the 
latter part of h*is paper, in which he states that it was 
not until after the expiration of the second patent of Mr. 
Roberts and that of Mr. Smith that a really good working 
