928 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



consumed in trials witli tliis machine, anct tlie most discouraging i^rac- 

 tical difficulties were brought to light. It Avas not till long afterward 

 that tlie inventor could discover the projyer modes of obviating these diffi- 

 culties. Nevertheless, this first small machine served as a complete 

 verification of the facts, principles, and numerous small exi^eriments which 

 had been relied upon; and it thus became an encovuagement in the end 

 to attemi^t a vastly larger construction." 



On the loth of February, 1855, an engine calculated to produce 2,000 

 pounds of ice i)cr day in ten freezing-cisterns of cast iron, each divided 

 into seven water-chambers, was in readiness for trial. With only two 

 cisterns of the ten, 371 pounds of ice were made in eight hours. The 

 water employed for condensation was thirty times in quantity the water 

 frozen. In the vacuum-vessel the tension of vapor began with 5.7 inches 

 of mercury and ended with 2.7 inches. In the condenser, the tension 

 rarely exceeded 2 pounds above the atmosphere. The i^iunj) was Sc- 

 inches bore and 18 inches stroke, working 1)0 double strokes per minute. 

 On the 2d of March, 1855, GGl i)ounds of ice were made in eleven hours 

 and ten minutes with only four cisterns. In different trials during the 

 summer, eight cisterns of the ten were put on. The machine would at 

 any time freeze up in these cisterns 50 cakes of ice, each 1 foot square and 

 6 inches thick, and weighing together 1,080 pounds. With ten cisterns, 

 a ton could be frozen. 



The great merit of Professor Twining's invention was extending the 

 surface over which ice could be formed, by extending the ''freezing-cis- 

 tern" containing the ice-moulds, and using an uncongealable liquid which 

 was stagnant around the moulds. This was the great advance on Mr. 

 Jacob Perkins. In a patent issued April 22, 1862, he claims a immp to 

 agitate or circiQate the uncongealable liquid. Twining described in 1852, 

 but a patent was only issued on the 15th of April, 1802, the method of 

 using a refrigerator, as in the Harrison machine, with vertical tubes closed 

 beneath or entering a eul de sac, allowing the ether to run dow^u and its' 

 vai)or to escape upward. The vaporized li(piid thus abstracts heat from a 

 contiguous uncongealable liquid that surrounds the pipes, and in its cold 

 state is drawn out by a circulating-pump in i)lace of running the cold 

 volatile Uquid through the freezing-cistern. This pump circulates the 

 brine in open troughs which contain the water-vessels. Professor Twin- 

 ing aimed at extending surfaces, and for this he had described a percolator. 

 He had perforations, or i)erforated branches or channels, girdling every 

 exposed side of each icater-chamher, and made to inject the ether in jets, 

 or drops or films, upon or between its exposed surfaces or coatings. The 

 volatile liquid thus spread upon or running down the water-chambers 

 freezes through the imcongcalahle liquid and the icater-vessels in those 

 chambers. 



Mr. James Harrison, of Geelong, Austraha, did excellent worli in his 

 investigations of this subject, and so instructive are his specifications 

 that thej^ may be said to constitute the most substantial contributions to 



