Inventions almost similar in Form, but different in Principle.

Pavement lights, like those used in decks of ships, had been made of such form that the light passing through was refracted and so spread in the space below. An improvement consisted in so shaping the glass prisms that one side acted as a reflector. Thus the principle of internal reflection of light was brought into play. See Hayward v. Hamilton, post, p. 277.

A new disinfector consisted of an inner disinfecting chamber and an outer chamber, to both of which steam could be introduced. The alleged anticipation consisted of the same elements. But the new one was constructed of such strength that superheated steam under considerable pressure could be employed, thereby greatly accelerating the process. The invention was novel. See Goddard v. Lyon, post, p. 358.

See Chamberlain v. Bradford (Mayor of), post, p. 467.

On the other hand, if the same principles be applied, and in the same manner, then the inventions will be identical, although their outward form may at first sight appear quite different.

Inventions different in Form, but identical in Principle.

The

The invention in question was Messrs. Gaulard & Gibbs' system of distributing electricity. It consisted in having an alternating current of high tension in the main, from which branch currents of low tension for use were taken off by means of transformers. anticipation consisted of the use of transformers in Jablochhoff's system, in which the transformers were used for giving high tension currents to each lamp, so that each might be independent of the others. The later patent was invalid. See Gaulard & Gibbs' Patent, post, p. 329.

A mechanical stoker was constructed so that the coal was projected over the fire by means of doors on a shaft and moved intermittently so that when in operation they moved radially. The operating mechanism was applied to the shaft. Another stoker was constructed in which the door was replaced by a curved arm having a flap at its lower end. It was moved intermittently by mechanism inside the curved part instead of outside on the shaft. The radial action against the coal was the same. The second invention was held to be a mere colourable imitation of the first. See Proctor v. Bennis, post, p. 305.

In the more complex or "combination" inventions the ultimate principles may be the same, but the manner of their application in

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the old methods or processes and in the new combination may not be the same. In such cases the comparison is made between the proximate principles or "elements" of the combination. If the elements be so combined in each case that the corresponding parts perform the same functions, then the inventions are identical, otherwise not. As the respective inventions consist of the combining together of certain elements, the nature of the combination is tested by the result of that combining, that is, by the functions discharged by the elements in the two combinations respectively.

Inventions in which the Combinations were apparently identical, but in which the Parts performed Different Functions.

The patent in question was for improvements in fire-proof floors. Flanged tubular lintels were so shaped and laid across the girders that the latter were covered with the concrete subsequently poured in. Alleged anticipations were similar. But owing to the lintels being placed askew they enabled the concrete to form in part a self-supporting arch from girder to girder. The older ones did not perform this function. The patent was upheld. See Fawcett

v. Homan, post, p. 383. In Welch's patent for securing rubber tyres wires were employed embedded in the cover and lying in the rim of the wheel. An alleged anticipation showed a similar contrivance. But Welch's wire operated by resisting extension due to air-pressure or by excercising contractile force on being screwed up. The other did not exercise this function. The patent was held valid. See the Pneumatic Tyre Co. v. East London Rubber Co., post, p. 425.

Another form in which there may be a difference in the manner of the application of the same principle is in the extent to which the principle may be applied. If carried further in one case than another so as to produce different results, then the manufactures may be different.

Application of Same Principles, but to a Greater or Less Extent to produce a Different Result.

The patent was for an improved grooved tyre for wheels.

The object

was to produce by a cheap method an iron tyre with a dovetailed section for holding a rubber tyre. The method consisted in passing iron through a series of rolls, finally rolling the base flat to produce the required result. An alleged anticipation consisted of rolling by a similar method iron trough-shaped beams in which

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no dovetailed section was required. This alleged anticipation did not carry the principle of successive rollings far enough, nor did the claim for the new tyre include the earlier stages of the process. See Shrewsbury & Talbot Cab Co. v. Sterckx, post, p. 377. [The article produced was a different one, i.e. a new manufacture.] A dye substance was made by a certain process. It was discovered that if the process were stopped at a certain stage, a dye substance was produced possessing different properties but giving substantially the same colour. The shorter process was a patentable invention. Leonhardt v. Kalle, post, p. 362. [The resulting new dye substance possessed properties different to the old, and the newer method constituted a different process or manufacture.]

Minimum of Addition to Public Knowledge essential.

The consideration of that addition to the stock of public knowledge which is necessary and sufficient to constitute a patentable invention is a question of considerable difficulty. As has already been pointed out (ante, p. 20), a patent would be to "the hurt of trade," and "generally inconvenient," if it were granted for inventions (although actually "new manufactures") of so simple a nature that the monopoly so created would prevent skilled workmen from making the best use of the knowledge they already possessed. All new inventions must be the outcome of the inventive faculty of the mind (unless discovered accidentally or imported from abroad), hence it becomes a question of degree as to the amount of ingenuity required to support a patent. This amount of ingenuity is frequently termed "invention." 3

The term "invention" is therefore used in more senses than one, and very generally to denote the manufacture patented (ante, p. 6) and also in recent years to denote the amount of ingenuity required to support a patent. In each case the context will show in which way the term is to be understood. There is a distinction between discovery" and "invention " used in the latter sense. One may discover either (1) a new principle, or (2) a new quality of a body, or (3) a new use to which old appliances may be put. Whether the

1 Harwood v. G. N. Ry. Co. (per Lord Westbury, L.C.), 11 H. L. Ca., at p. 682; Murray v. Clayton, L. R. 7 Ch. Ap. 577 n; Saxby v. Gloucester Wagon Co., 7 Q. B. D. 312. 2 Per Blackburn and Shee JJ., in Harwood v. G. N. Ry. Co., post, p. 207. to Morgan v. Windover, post, p. 324.

See note

* See remarks of Bramwell and Brett, L.JJ., in Hayward v. Hamilton, post, p. 280; also of Smith, L.J., in Brooks v. Lamplugh, post, p. 410; and cases reviewed by Lindley, L.J., in Gadd v. Manchester, 9 R. P. C. 524, post, P. 354.

subject of a "discovery" be a patentable invention or not depends on whether it be a new manufacture1 (ante, p. 9), and one not obvious to skilled workmen when their attention is called to the necessity of producing a desired result; 2 or whether it be merely a principle or new use of an old manufacture.

The existence of inventive ingenuity is a matter of evidence. If there be evidence that skilled workmen could effect the invention in question without difficulty as soon as their attention is called to the need of it, then there is obviously no "invention." On the other hand, the fact that skilled persons sought in vain to solve the problem solved by the patentee is proof of sufficiency of ingenuity.3 But the large majority of cases are those in which such evidence is not directly available, hence the necessity for ascertaining the sufficiency of ingenuity by other considerations, and by comparing the invention itself with what was known before.

Since, for the protection of skilled workmen, a certain minimum amount of knowledge is required to be added to the public stock by an inventor to maintain his patent, it is from the point of view of the workman that the question is to be considered. Therefore it does not matter if the patentee imported his invention from abroad (post, p. 48), or discovered it accidentally, or only arrived at it after prolonged experiment. On the other hand, an inventor may, after much trouble and experiment, only arrive at a result that is not patentable, because it is no advance on what others, unknown to him, had already achieved.5

Illustrations.

The invention in question consisted in the mode of supporting the front of a carriage by C springs, formerly used at the back. It was proved that carriage-builders could effect this without any difficulty. The patent was invalid. See Morgan v. Windover, post, p. 323. An invention, very simple when known, consisted of a mechanical combination for turning heavy forgings. Many unsuccessful attempts

1 As to discovery of qualities of a new alloy : Tindal, C.J., in Muntz v. Foster, 2 Webs. 103; Pirrie v. York St. Flax Spinning Co., 11 R. P. C. 449.

2 See generally the remarks of Lindley, L.J., in Lane Fox v. Kensington, &c., post, p. 350, and in Gadd v. Mayor of Manchester, and notes, post, pp. 354, 355.

* See Lord Herschell's observations in Vickers v. Siddell, post, p. 328, and those of Lord Halsbury, L.C., in Taylor v. Annand, post, p. 449; also Gosnell v. Bishop (per Bowen, L.J.), 5 R. P. C. 158.

▲ Crane v. Price, post, p. 197.

For an example, see Riekmann v. Thierry (per Lord Davey), post, p. 394.

had been made to "meet the want" supplied by the device in question. The patent was upheld. See Vickers v. Siddell, and notes, post, pp. 324, 329.

A patent for an invention consisting of very simple mechanical improvements was upheld by the Inner House of the Court of Session on the ground that other inventive minds had been at work and failed to get over the difficulties surmounted by the patentee. White v. Bertrams, 14 R. P. C. 746.

See also Taylor v. Annand (per Romer, L.J. and Lord Halsbury, L.C.), post, p. 449, in which the existence of sufficiency of inventive ingenuity was proved in a similar way.

This necessary addition to the amount of public knowledge may be apparently very little-the alteration in shape (or the introduction of an equivalent 1) in a mechanical contrivance producing new and better results by causing a difference in the operation of mechanical forces; or alteration in shape or strength of mechanical devices bringing new physical principles into operation; or alteration in physical conditions giving rise to new chemical reactions and improvements in processes or the production of new substances. But a large number of inventions consist in new combinations (ante, p. 16), arrangements, or applications of old and well-known things or processes. These it will be found more convenient to consider separately (post, pp. 38-46).

In those cases in which previous failures have been turned into successful processes or results, the amount of ingenuity may be apparently very little, but the invention itself be great; 2 for the previous attempts may not be "knowledge" at all (ante, p. 27).

Alterations of Shape or Strength constituting New Invention.

A new form of "flyer" for roving cotton applied known forces in a different way, producing steadier working of the machine. See Seed v. Higgins, post, p. 212.

New effects in pavement lights produced by alteration in shape bringing into play a different natural phenomenon. See Hayward v.

Hamilton, post, p. 277.

Strengthening the structure of a disinfector to utilize dry steam under high pressure. See Goddard v. Lyon, post, p. 358.

1 Per Lord Halsbury, L.C., in Vickers v. Siddell, 7 R. P. C. 303, l. 17.

2 Hinks v. Safety Lighting Co., post, p. 257. For instances of the application of this principle, see cases noted, ante, p. 28; also Duckett v. Whitehead, post, p. 370.