68 MADRAS FISHERIES BULLETIN VOL. XIII, 



vertical like the autoclave or rectangular and horizontal, is used ; 

 in this latter case the cans are placed on trollies which are run on 

 rails up to and into the retort which is then closed steam tight and 

 open steam is let into the retort. 



66. Both these methods are in use at Beypore, but as operations 

 are not very extensive the autoclave is generally used. The 

 autoclaves may be of varying sizes, but usually hold 200 to 400 

 cans. The autoclave at Beypore measures 22" in diameter and 29" 

 in depth and is now set in brick work over a wood burning grate; 

 the brick work is banded with iron to minimise cracking and its 

 effects ; it has two cages (one being loaded while the other is in 

 the autoclave), and each cage will take 380 quarter cans or 200 

 12 oz. cylindrical cans. It is well to have two autoclaves so 

 as to deal with a rush of fish and to have one in reserve. The 

 processing in such autoclaves (or retorts) may take an hour for each 

 batch from start to finish, the actual steaming at the desired 

 pressure being from 30 to 45 minutes according to the nature of the 

 cans and their contents ; hence in four hours two small autoclaves 

 of 300 quarter tins each, could cook 2,400 such tins. 



67. Retort steaming is somewhat quicker and as the retorts 

 usually take more cans than the autoclave, a single retort suffices 

 for, say, 4,000 quarter tins per four charges. The Beypore horizontal 

 steam retort measures 72" x 30" x 30" and will take 1,100 quarters. 

 The trays of cans are piled on the trollies provided with the retort ; 

 these trollies rest on trucks (made at Beypore) which travel in a 

 run-way to the mouth of the retort where the trollies are pushed 

 inside on rails provided in the retort. The retort should be well 

 lagged. When externally steamed retorts are used a separate 

 steam boiler is" needed which will also steam the steam frier (if 

 such is in use), and the testing and exhausting vats and any other 

 boiling pans when pressure cooking is not desired. Moreover, if 

 there are power-driven machines the boiler is required by the 

 engine. The size depends on the work to be done, but it is well to 

 have a surplus of evaporative power, so that various items may be 

 steamed at once. If a boiler with 6 square feet of grate is deemed 

 generally sufficient it is well to buy one with 7 or 8 square feet to 

 provide for ' peak ' needs. The boiler should have a working 

 pressure of 100 lb., for though only II or 12 lb. are needed 

 in the retorts and the steam for the steam frier, if in use, is 

 generally superheated, there may be machines to be driven, and in 



