No. 2 (1921) REMARKS ON CANNING 69 



any case, the surplus working pressure affords a margin of safety 

 in case of careless attendants. The Beypore boiler is only 4 N.H.P. 

 (about 4 square feet of grate) which will not steam the retort and 

 vat and siiniiltaneoiisly drive the solderless plant or the 5 I.H.P. 

 engine with a load. ' 



Water should be laid on to the processing room not only to 

 supply the autoclave and vats, but to provide for cooling the cans 

 after leaving the steam kettles or the vats. It should of course be 

 laid on to the boiler shed. 



68. Plant for fish pastes- — Small but special plant is needed for 

 fish pastes if those are manufactured. It will be best understood 

 when the manufacture is described below (paragraphs 196— 205) but 

 consists of boiling pans or steaming chambers for steaming the 

 fish, dishes, forks, etc., for removing the flesh from the bones, 

 cutters with plates of various apertures for disintegrating the flesh, 

 marble or slate topped tables for rolling out paste and ingredients, 

 glass churns for mixing milk, melted butter, water, spices, etc., into 

 an emulsion, stone mortars for further comminuting the paste, 

 small grinding machines for grinding pepper and other spices, 

 dried bread, etc., and so forth. The tins used are small cylindrical 

 tins, capped or strip off as mentioned above, but with sets of small 

 dies it should be easy to make small solid drawn tins in presses 

 such as are available at Beypore, or semi-solderless cans with lock 

 seams at side and seamed tops and bottoms ; see supra s.v. 

 ' sanitary ' cans. 



69. Thermometers. — At least half a dozen metal cased thermo- 

 meters marking to 220° F. are needed for testing the water in vats ; 

 it is astounding how often water declared to be at testing tempera- 

 ture (say, 180° — 190° F.) is shown by the thermometer to fall far 

 below those degrees with consequent liability to spoil the testing, 

 or how often when supposed to be boiling, is below 200° even at 

 sea level. Several similar thermometers but reading up to at (east 

 400° F. are necessary for testing the temperature of the oil in the 

 frying vat. If it is desired to determine without doubt whether 

 cans of given size and contents have reached the full sterilising or 

 high temperature during processing, and to decide scientifically 

 for what length of time and at what temperature cans should be 

 processed, it is necessary to provide a number of small self-recording 

 thermometers which can be wholly enclosed in the centre of 

 marked cans and placed centrally in a batch ; after processing, these 



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