Weaving. 459 
obtained for an invention already invented : no man can legally 
obtain a patent under our federal laws, for merely introducing a 
process or machine invented elsewhere.* 
To the best of my recollection, neither in Mr. Cartwright’s or 
in Mr. Janes’s loom was there any contrivance that the work 
should stop when a thread broke. While the thread continued 
whole in the shuttle, the work was good ; but when it broke, and a 
boy was not at hand to stop the motion, the work went on indeed, 
but was defective. This defect I saw obviated by a very ingeni- 
ous contrivance in a loom constructed by Mr. Siddal, and at work 
about 5 or 6 miles from Philadelphia, at the Calico printing works, 
near the old York Road. For this invention I believe Mr. Siddal 
has obtained a patent, and the inventor of it certainly deserves one. 
The most profitable (that is permanently profitable) manufac- 
ture any person can enter into in this country at the present time, 
is an establishment that should combine the carding, the spinning 
of cotton — the weaving by looms similar to those mentioned above, 
of plain calicoes, shirtings, sheetings and table cloths — the new 
* Extract of a letter from a friend. “ You may have noted that the pa- 
tent board, while it existed, had proposed to reduce their decisions to a sys- 
tem of rules as fast as the cases presented should furnish materials. They 
had done but little when the business was turned over to the courts of 
justice, on whom the same duty has now devolved. A rule has occurred to 
me which I think would reach many of our cases, and go far towards se- 
curing the citizen against the vexation of frivolous patents. St is to consider 
the invention of any new mechanical power, or of any new combination of 
the mechanical powers already known, as entitled to an exclusive grant ; but 
that the purchaser of the right to use the invention, should be free to apply 
it to every purpose of which it is susceptible. For instance, the combination 
of machinery for threshing wheat should be applicable to the threshing of 
rye, oats, beans, &e. the spinning machine to every thing of which it may be 
found capable : the chain of Buckets, of which we have been possessed 
thousands of years, we should be free to use for raising water, ore, grains, 
meals, or any thing else we can make it raise. These rights appear suf. 
iiciently distinct, and the distinction sound enough to be adopted by the 
Judges, to whom it could not be better suggested than through the medium 
of the Emporium, should any future paper of that work, furnish place for 
the hint.’* 
I have no doubt whatever of the justice of these Ideas, or of the propriety 
of adopting them. T. C> 
3 I. 
VOL. Ill, 
