EEPORT OF THE COMMISSIONER OF FISHERIES. 157 



less than three or four cans under the acid chain, and ten or twelve 

 -under the soldering- chain. Much depends on the operator of these 

 two machines, and only those who have had considerable experience 

 are intrusted with this work. A watchful eye must be kept on all the 

 cans as they pass through, to be sure that the proper amount of solder 

 is received. With all the caution that is taken, an occasional top is 

 J)lown off, and once in a while a rim will start, which necessitates repairs 

 and a repetition of the process. Very often several cans require atten- 

 tion at once, although to the inexperienced eye the}^ ma}^ be as perfect 

 as any of the others. 



The old style of soldering machine was built over a brick furnace, 

 coal being used as fuel, and man}^ of this type are still in use. The 

 apparatus is 8 feet long, about 5 feet high, and 3 feet wide, however, 

 and the amount of space required is an objection. The modern machine 

 occupies no more space than the chain and trough of the old one; in 

 fact, the later improvement in this style is the chain and trough minus 

 the brick furnace. The heating apparatus is a row of kerosene blast 

 jets (T in number) arranged directly under the trough, the oil and air 

 pipes running parallel. The machine can be taken apart in a short 

 time and set up again in any part of the building. 



The improved chain soldering machines, however, are rapidly being 

 supplanted by the spiral and linger sprocket machines. These inven- 

 tions are of recent date, and are said by canner}^ men to be superior to 

 the old forms. The new soldering machines have greatly expedited 

 the vrork in canneries, and have been the means of reducing the num- 

 ber of leaky cans to a minimum, also of producing results much neater 

 in appearance. 



Testing. — On leaving the soldering machine, the cans roll down a 

 wooden chute about 40 feet long, passing under several jets of water 

 to se^t the solder. Some canneries use Manula's revolving cooler, a 

 recent invention which practically does away with the long trough 

 leading from the soldering machine. The disk upon which the cans 

 rest is hollow and filled with running water. After making two revo- 

 lutions, the cans are forced into an inclined trough under a stream of 

 water. At the end of the chute are stationed two men who place the 

 cans in coolers, or crates, which are made of flat strap iron, square 

 shaped, and hold about 114 cans. The cooler having been filled, it is 

 placed upon a truck and rolled aside, where the vent holes are stopped 

 with a drop of solder. The cans are now ready for the test kettle, or 

 bath, a wooden box filled with water kept near the boiling point by 

 steam pipes arranged at the bottom. The coolers are hoisted into the 

 test kettle by block and tackle attached to an overhead track, which 

 permits the coolers to be swung to any place desired. From two to 

 three minutes is required for the hot leak test. 



