current at a constant pressure; so far as the lamps were concerned it was immaterial whether a return conductor was used or the earth. Throughout the specification the "earth" was spoken of. Held, on the authority of the above case, that an earth-return was not claimed as essential to the system of distribution. Lane Fox v. Kensington, &c., 9 R. P. C. 242. The decision in El. Tel. Co. v. Brett did not turn on the allegation that the earth-return was an "equivalent" for the metallic, but that the metallic return, not being an essential, was not necessarily included in the claim.

1855. HEATH 7. UNWIN, 5 H. L. Ca. 505.

Construction-Chemical Equivalents.

In 1839 a patent was granted to J. M. Heath for " certain improvements in the manufacture of iron and steel." The nature of these inventions was: (1) extraction of pure cast iron and formation of slag, (2) forming cast steel from the cast iron by fusing with malleable iron and certain oxides, (3) the use of oxide of manganese in puddling, and (4) "the use of carburet of manganese in any process whereby iron is converted into cast steel." The several processes were described in detail, including the use of oxide of manganese in the puddling furnace, and, "lastly, I propose to make an improved quality of cast steel, by introducing into a crucible bars of common blistered steel, broken as usual into fragments, or mixtures of cast and malleable iron and carbonaceous matters, along with from one to three per cent, of their weight of carburet of manganese, and exposing the crucible to the proper heat for melting the materials, which are, when fluid, to be poured into an ingot mould in the usual manner; but I do not claim the use of any such mixture of cast and malleable iron, or malleable iron and carbonaceous matter, as any part of my invention, but only the use of carburet of manganese in any process for the conversion of iron into steel, I claim. . . and, fourth, the employment of carburet of manganese in preparing an improved cast steel."

Carburet of manganese was a substance manufactured by heating at a high temperature oxide of manganese and carbon.

It was subsequently discovered, but not known at the date of the specification, that if black oxide of manganese and coal tar were made into a paste in suitable proportions and introduced into the furnace, the result would be the same as the direct use of carburet of manganese. There was no direct evidence that carburet of manganese was actually formed in the melting process, but such was the opinion of experts.

The opinion of the judges was called for by the House of Lords. Parke, B. (p. 538): "The specification must be read as persons acquainted with the subject would read it at the time it was made; and if it could be construed as containing any chemical equivalents, it must be such as are known to such persons at that time; but those which are not known at the time as

equivalents, and afterwards are found to answer the same purpose, are not included in the specification; they are new inventions.” 1

Held, by the House of Lords (reversing the Court below): That the specification claimed only the use of the carburet of manganese, and did not include the use of the coal tar and oxide paste.2

Notes.

This decision was one in a case where the patent was for a new process (use of carburet of manganese) for attaining an old result (formation of steel); there is no analogy between it and a case where the chemical combination is part of a larger novel combination. Incandescent Gas Co. v. De Mare, &c., 13 R. P. C. 332.

1858. NEWALL v. ELLIOTT, 4 C. B. N. S. 269; 27 L. J. C. P. 337.

Prior User and Publication-Disconformity.

In 1855 a patent (No. 1091) was granted to R. S. Newall for "improvements in apparatus employed in laying down submarine electric telegraph wires." The provisional specification was in the following terms:

"This invention consists of apparatus combined and acting in the following manner: The cable or rope containing the insulated wire or wires is passed round a cone, or, if it is a long cable, round several cones, so that the cable in being drawn off the coil is prevented from kinking by means of the cone, and there is a cylinder on the outside which prevents the coil from shifting in its place. The cable passes over a pulley above the cone and on to a brake-wheel, round which it takes several turns to obtain sufficient holding, and from the brake-wheel it passes over the stern of the vessel on board which the cable or rope is placed; or I use two or more brake-wheels, the one behind the other; the cable or rope comes up from the hold of the vessel and round the first brake-wheel several times, then on to the second brake-wheel, round which it also takes several turns. When the brake is applied to the first wheel it increases the friction on the second, and so on, according to the number of brake-wheels used; or I use two brake-wheels, coupled together either by spur gear or cranks and connecting-rods; the cable in such case passes round only a part of the circumference of each. There are grooves in the wheels, which guide the cable or rope from one to the other, and prevent its getting foul; or a guide is used to push the cable from one side of the wheel to the other, so as always to keep one part from riding over another."

The complete specification began by a repetition of the provisional, and then continued:

Quoted as authority in Badische Anilin, &c. v. Levinstein, 24 Ch. D. 170; 2 R. P. C. 90. ? The decision turned in a great measure on the construction of the specification, inasmuch as the precise proportions of carburet and iron to be introduced were given.

202

cables

"The greatest difficulty in laying down submarine telegraph wires or hitherto has been the limit to speed in paying them out, arising from the necessity of the leading off part of the coil being kept clear the others, by a great number of men handling it to prevent its

becoming

This

reted by coiling the wire or cable round a cone (or several cones if so that the wire in being drawn off the coil is prevented from required), kinking by means of the cone.

The apparatus I employ is shown in the

accompanying drawings, which represent a section and plan. A, B, C, D

even

Part of drawing of Newall's specification (1091 of 1855).

is the cone; it is formed of wood, or it may be of iron, so as to present an surface on the outside, so that the wire in passing round it may not be caught by any projection. This cone is firmly fastened to the bottom of the vessel, and reaches at least as high as the top of the coil. Around the cone is formed a cylinder or series of uprights m, strongly fastened to bottom and deck, so as to prevent the coil of wire or cable which is from shifting in its place. coiled around the

the

cone

brake wheels on the left. The error in the drawing

A strong iron ring or elevation in part. The original

For the present purpose it is only necessary to show the, showing a ring too close on the introduced into the 2nd edition of the specification published by the Patent Office.

showed

cone

was

Over

hoop is fastened outside the supports to brace them together at ”. the cone is placed a pulley, one side of it being in a line with the axis of

the cone."

The position, strength, and proportions of the brake-wheels were described, and then the coiling of the cable, as follows:

"The cable is carefully coiled round the cone in horizontal layers, beginning from the outside next the cylinder and coiling towards the cone, When the space is filled up, the bight of the rope is taken to the outside of the coil at b, and another layer is coiled, and so on, until the whole length

is coiled round the cone.

"When the wire or cable is to be laid down, I place over the Cone an around this I suspend several rings of iron or other metal by means of cords, apex or top, which is conoidal, as shown in the drawing, or conical, a an so as to admit of adjustment at various heights over the cone, as at

The

use of these rings is to prevent the bight of the rope from flying out when going at a rapid speed, and the combination of these parts of the apparatus

nearest

Pectively

prevents the wire or cable from running into kinks. The two rings the coil are lowered, so as to be about six inches and a foot resp above the coil as it is being paid out."

Directions were next given for leading the cable through the rings over the pulley and round the brake-wheels. The action of the latter when the cable was paid out was described.

The claims were :—

"First, coiling the wire or cable round a cone.

“Second, the supports placed cylindrically outside the coil round the

cone.

66

Third, the use of rings in combination with the cone, as described.” Before the date of the patent solid cores had been used in the processof manufacture and for keeping the cables in position during transit, but not when being paid out. Before being laid cables were coiled in circular tanks for testing purposes. When being laid, successive layers were tied together in coils in the hold. As the cable was running out men were employed to cut these fastenings and handle the cable to prevent kinks.

It was found necessary to have an experimental test made at sea, and laying the cable in deep water, before it could be regarded as a successful invention. In fulfilment of a contract with the Government (to be carried out under the supervision of a naval officer, and to be certified by an engineer), the plaintiffs stowed the cable in the manner described in the specification on board the Black Sea. Having to return through stress of weather, the cable was shipped from the Black Sea to the Argus in the Thames, and similarly coiled on board the latter vessel. In spite of precautions for secrecy, persons other than employés had opportunities of seeing the invention. No use, however, was made of such knowledge. The apparatus in laying a cable in pursuance of the contract in the Black Sea, and subsequently the patent was applied for. At the trial, amongst other objections to the validity of the patent, 1

those

"The greatest difficulty in laying down submarine telegraph wires or cables hitherto has been the limit to speed in paying them out, arising from the necessity of the leading off part of the coil being kept clear of the others, by a great number of men handling it to prevent its getting into kinks or becoming entangled one part with another. This is remedied by coiling the wire or cable round a cone (or several cones if required), so that the wire in being drawn off the coil is prevented from kinking by means of the cone. The apparatus I employ is shown in the accompanying drawings,' which represent a section and plan. A, B, C, D

is the cone; it is formed of wood, or it may be of iron, so as to present an even surface on the outside, so that the wire in passing round it may not be caught by any projection. This cone is firmly fastened to the bottom of the vessel, and reaches at least as high as the top of the coil. Around the cone is formed a cylinder or series of uprights m, strongly fastened to the bottom and deck, so as to prevent the coil of wire or cable which is coiled around the cone from shifting in its place. A strong iron ring or

1 For the present purpose it is only necessary to show the elevation in part. The original showed brake wheels on the left. The error in the drawing showing a ring too close on the cone was introduced into the 2nd edition of the specification published by the Patent Office.