No. 2 (1921) REMARKS ON CANNING 55 



but consists of oil, etc., dissolved in a volatile spirit; this when 

 applied either by hand or by a * lining ' machine and dried 

 provides a continuous and elastic washer unaffected by oil. In 

 Beypore the rubber is now to be protected by a solution which will 

 indirectly improve the sealing and the life of the joint. 



The machines installed at Beypore can make and close under 

 Indian conditions some 2,000 solderless cans per working day 

 provided that fish are available early in the day and continuously ; 

 a second double seamer worked by one man would double the 

 output as the other machines can be worked at various times and 

 thus store up cans. 



The power is given by a 5 I.H.P. engine. 



41. Scmi-solderless cans are cans which are partly seamed, partly 

 soldered, the solder being less or more according as the seams are 

 or are not provided with composition gaskets inside the seam. 

 This class of can includes the United States of America ' sanitary ' 

 can, so called because it does away with the possibility of conta- 

 minating the contents by solder or by the fluxes of which some are 

 poisonous. The sanitary can is mainly a cylindrical ' tall ' can 

 such as is used for salmon, preserved fruits, jams, soups, etc.; the 

 cylinder is formed as usual from a strip of tin plate, but the junc- 

 tion is effected not by a line of solder as in a soldered sardine tin, 

 but by a lock seam formed by folding or interlocking one edge 

 with the other; the locked or folded seam is at the same time 

 squeezed flat by a grooving arrangement so as to form an almost 

 air-tight joint; if a composition washer or a solution has been 

 interposed the joint is hermetical as described s.v. ' solderless ' 

 cans, but otherwise an external wash or floating of thin solder 

 completes the sealing of the joint. The cylinder is provided with 

 a flange at the top and bottom produced by the machine when 

 forming the body ; the bottom ^at is then seamed on, with or 

 without a sealing gasket, in the usual way by a double seamer. 

 For many goods which do not taint or ferment a plain seam with- 

 out a washer is sufficiently air-tight, but for goods requiring 

 hermetical sealing the seam is either sealed with the usual inter- 

 posed washer or by an external application of thin solder. The 

 can which is thus a cylinder open at the top to its full width, is 

 then packed with the goods, and the cover, which is a replica of 

 the bottom, is sealed on to the flanged top in the same way as the 

 bottom. This provides a can sealed by seaming, and rendered 



