delivered the opinion of the court:
The patent here sought is for alleged improvements in boiler structure. There are two claims at issue, Nos. 5 and 6, which read as-follows:
5. A boiler wall structure of the character described comprising a multiplicity of rolled structural channel beams arranged flange to flange alongside one another and having separately formed U-shaped caps united to the edges of the channel flanges and nipples in the flanges of the channels adapted to establish communication between the chambers formed by said members.
C. A boiler wall structure of the character described comprising a multiplicity of rolled structural beams each having a rigid web and integral flanges substantially perpendicular thereto and separately formed caps united to the edges of the flanges and nipples establishing communication between the chambers formed by said members.
The claims were rejected by the examiner whose decision was affirmed by the Board of Appeals of the Patent Office. Appeal was then taken to this court.
The references to prior art cited are:
McClellon, 764753, July 12, 1904.
McClellon, 963627, July 5, 1910.
Murray, 1186222, June 6, 1916.
In its decision the board said:
Claims 5 and 6 are objectionable for the reason that they involve the limitation of an article claim by the method of making it. The article, as claimed, differs from the boiler fire wall disclosed in the patents to McClellon only in the fact that tlie tubes are made by welding together at tlieir edges two forms of rolled structural material, such as a channel bar and a semitubular section. When so welded together the tube is no different from one which is formed from a tube having its sides flattened to produce abutting surfaces when brought together to form the fire wall. Such tubes are used in McClellon No. 903627 (see p. 1, lines 83 to 85) and it is stated in No. 764758 that the tubes 12 may be made of various shapes in cross-sectional contour though it is preferred that this be square exteriorly. (See p. 3, lines 11 to 14.)
If a claim were drawn to the method of making a tube by welding together the edges of two rolled structural elements it would be met by appellant’s patent No. 1186222, cited by the examiner.
It is observed that McClellon in patent No. 764753 discloses a locomotive boiler with flat-sided water tubes composing the sides of the fire box. The specifications state that the tubes “ may assume various shapes in cross-sectional contour, although I prefer the tubes that are square exteriorly.” A figure of the drawings shows tubes which are square both exteriorly and interiorly.
*1128McClellon’s patent No. 963627 is for a fire box for boilers which shows sections having curved sides joined by flattened sides. These .are fitted together to form the walls. Nipples are shown which permit the water freely to circulate through the connected sections.
The reference patent to Murray relates to a method of electrical welding. In view of the fact that the claims in the present case do not mention welding this reference is not thought to have any particular pertinency here, but we are unable to see any error in the holding of the Board of Appeals which, in effect, is that appellant’s tubes, when finished by having the separately formed U-shaped caps united to the edges of the channel flanges, do not present any differences of a patentable nature from McClellon’s tubes flattened to produce abutting surfaces.
The decision of the board is, therefore, affirmed.