machines, amounts to invention and should be protected. by the patent law.

9. Invention by Change of Proportions.

Many instances of invention consisting of a change of proportions are found in chemical combinations and compositions of matter. Take for example the case of the combinations of india rubber and sulphur. Charles Goodyear discovered that when crude or natural india rubber was combined with sulphur in comparatively small quantities, (from 6 to 20 per cent of the weight of the rubber) and the compound was heated, it became what is now known as soft vulcanized rubber, having the properties of pliability and extensibility of the original rubber with additional qualities or properties. Thus, the changed product was far less affected by heat and cold than crude rubber; and before it was subjected to the vulcanizing heat, it was in an inelastic putty-like condition in which it could be moulded into useful forms and could be thinned by a solvent so as to be spread on cloth. His patent was dated June 15th, 1844, and was reissued.

Subsequently, Nelson Goodyear discovered that if the proportions of the same two materials were changed by increasing the sulphur to 25 per cent and upwards of the rubber, the compound upon being subjected to heat lost the soft pliable quality of crude rubber and assumed the properties of horn, being non-extensible (by ordinary strains) and susceptible of being polished, and becoming in fact the substance known as hard rubber or vulcanite. The original patent for the new compound was granted May 6th, 1851, and was subsequently corrected by reissue. This improvement was decided to be

an invention. Goodyear v. New York Gutta Percha & I. R. Vulcanite Co., 2 Fish. Pat. Cas. 312. In this case the change in proportions of the same two materials, rubber and sulphur, was attended with a change in the properties of the article and consequently in its mode of operation; and there can be no doubt that in such case the change even in proportions is not a mere change, but is a material and substantial one amounting to invention. On the other hand, if the change in proportions makes no change in the properties of the compound or in its mode of operation, then the change is a mere change and does not amount to invention.

§ 10. Invention by Change of Material.

As an instance of change of material which is not a mere change we have the present common washing and wringing machine having its rolls covered with india rubber. In September, 1848, a patent was issued to John Young for an improvement in washing machines, subsequently reissued in 1861. There had been previous instances of rolls covered with cloth and with felt, both of which are more or less elastic; but the Young machine was the first in which the rolls were covered with rubber, which was not only elastic, as the roll coverings of cloth and felt were, but was impermeable to water. The change of material in this case introduced into the art of constructing washing and wringing machines of the roller variety a new property, that of impermeability to water; the change made in this class of machines was not therefore one of mere degree or of the mere substitution of one well known material (india rubber) for another equally well known, (felt) but was a change of kind, and the patent was sustained. This case demon

strates that although a mere change of material, that is, one in which the change is one of degree of old qualities, does not amount to invention, yet a change of material which imparts to a particular class of machines a new quality or property not previously possessed by that class, constitutes an invention.

§ 11. Invention by Change of Location.

As an instance of a change of location which is not a mere change, the product of mere mechanical skill, we may refer to the reaping machine of Seymour. The ordinary reaping machines of earlier date had comprised the following members, viz: a cutting apparatus extending across the front of the machine to cut the standing grain against which the machine was propelled, and a rectangular platform immediately behind the cutting apparatus to receive the cut grain as it fell; and the machine was used with an automatic rake which traversed the platform in a direction parallel with the cutting apparatus and perpendicular to the line of progression of the machine, and discharged the cut grain from it, delivering the grain at the side of the machine with the stalks parallel with the line of progression of the machine over the ground. This parallel delivery of the grain was objectionable for various reasons. There had been other reaping machines in which the cut grain after being raked from the rectangular platform was delivered upon a second platform of quadrantal form which was located at one end of the cutting apparatus and at the discharge end of the rectangular platform, and was fitted with an automatic rake whose teeth swept over the quadrantal platform in circular curves, so that the stalks of grain were partially turned and were delivered from

the quadrantal platform crosswise of the line of progression of the machine over the ground. This crosswise delivery of the grain is for various reasons better than the parallel delivery; but with machines of this second kind it is evident that two reaping platforms (the rectangular and the quadrantal) were required; also that two automatic rakes were necessary (one for each platform); and that the discharge of the cut grain from the place where it falls when cut is indirect, being first, crosswise of the line of progression of the machine, and second, in quadrantal curves.

Seymour's improvement consisted in locating or arranging a quadrantal platform directly behind the cutting apparatus, so that the cut grain could be swept by a rake directly from the cutting apparatus in circular curves, and was partially turned in its movement, and was therefore deposited on the ground with its stalks crosswise of the line of progression of the machine. This improvement therefore dispensed with one of the two raking platforms and with one of the two rakes of the second above variety of reaping machines, while at the same time it attained the beneficial delivery of the stalks of the grain crosswise of the line of progression of the machine.

In a suit under this Seymour patent one of the defenses was that the improvement did not involve invention, but merely the skill of the intelligent mechanic, skilled in the manufacture and use of harvesting machines; and this defense may be considered under two heads; first, that as both the rectangular raking platform and the quadrantal one were old, the change made by the patentee was a mere substitution of one old form of platform (the quadrantal one) in the place of

another old form of platform (the rectangular); second, that the change made by the patentee was a change of location of the old quadrantal platform, for whereas it had previously been located or arranged in a reaping machine at one end of the cutting apparatus, the change made was the location of it directly behind the cutting apparatus. That the change was not a mere substitution is evidenced by the fact that it was attended with a different mode of operation, resulting in the better delivery of the cut grain; that is, a delivery with the stalks crosswise of the line of progression of the machine instead of parallel therewith as effected by the use of the rectangular platform. That the change was not a mere change of location or arrangement is evidenced by the facts that the mode of operation was changed from indirect (as with the rectangular and quadrantal platforms combined) to direct; and that one of the two platforms and one of the two rakes, previously required when a quadrantal platform was employed in its old location, were dispensed with. The matter came before the United States Supreme Court upon appeal, and they decided that the change made by Seymour was a patentable invention. Seymour v. Osborne, 78 U. S. 11 Wall. 516, 20 L. ed. 33. It thus appears that when a change of location of an old device introduces a new mode of operation into the particular class of machines in which the change is made, or dispenses with a part of the old mechanism, the change is neither a mere substitution nor a mere change of location, but is a substantial change amounting to invention.

12. Invention by Change of Arrangement.

An instance of a change in the arrangement of old devices which is not a mere change is found in the