What was the patent for? (improved door knobs made of clay or porcelin)
Did knobs made of clay exist before?
What was NEW? (putting together known knobs and known spindle). So, combining known things. Found in paragraph starring with "The following bill of exceptions..."
What did the plaintiff argue? The combination took some skill and invention and was useful.
What did the defendant argue? There is nothing new in the combination.
What had the trial court done? Jury instructions that just a combination isn't new.
When should combining known things be patentable (not a law question, policy)? When the combination has new value and takes some skill. If it is useful and takes an investment, then there has to be an incentive or else others will copy it.
What did the Supreme court decide and what was the basis for their decision? The only thing new is the substitution of one material for another. It may be better, but it is only because of the superiority of the substitution of the material. "No one can pretend that a machine, made, in whole or in part, of materials better adapted to the purpose for which it is used than the material of which the old one is constructed, anf for that reason better and cheaper, can be distinguished from the old one, or, in the sense of patent law, can entitle the manufacturer to a patent." So, they are saying that a substitution of materials, not a combination of known things, prevents a patent.
What did the dissent say? The patent was for the COMBINATION of the knob and spindle. If the combination is "better" and "cheaper" and "new" then it should be patentable. NOT if an ordinary mechanic could have made it. Improvements like this "increase the power, convenience, and wealth of the community" and hence should be patentable. How much effort it takes doesn't matter, the invention could be totally accidental. It doesn't have to be complicated to be patentable. A NEW combination makes something new of value and hence can be patented, and no skill even to obtain them is necessary.