70 



HAWAII. 



[letter viii. 



well," however, and the delicate crystalline result makes one 

 forget the initial stages of the manufacture. The cane, stripped 

 of its leaves, passes from the flumes under the rollers of the 

 crushing-mill, where it is subjected to a pressure of five or six 

 tons. One hundred pounds of cane under this process yield 

 up from sixty-five to seventy-five pounds of juice. This juice 

 passes, as a pale green cataract, into a trough, which conducts 

 it into a vat, where it is dosed with lime to neutralize its acid, 

 and is then run off into heated metal vessels. At this stage 

 the smell is abominable, and the turbid fluid with a thick scum 

 upon it is simply disgusting. After a preliminary heating and 

 skimming it is passed off into iron pans, several in a row, and 

 boiled and skimmed, and ladled from one to the other till it 

 reaches the last, which is nearest to the fire, and there it boils 

 with the greatest violence, seething and foaming, bringing all 

 the remaining scum to the surface. After the concentration 

 has proceeded far enough, the action of the heat is suspended, 

 and the reddish-brown, oily-looking liquid is drawn into the 

 vacuum-pan till it is about a third full • the concentration is 

 completed by boiling the juice in vacuo at a temperature of 

 1 50°, and even lower. As the boiling proceeds, the sugar- 

 boiler tests the contents of the pan by withdrawing a few 

 drops, and holding them up to the light on his finger j and, by 

 certain minute changes in their condition, he judges when it is 

 time to add an additional quantity. When the pan is full, the 

 contents have thickened into the consistency of thick gruel by 

 the formation of minute crystals, and are then allowed to 

 descend into a heater, where they are kept warm till they 

 can be run into " forms " or tanks, where they are allowed to 

 granulate. The liquid, or molasses, which remains after the 

 first crystallization is returned to the vacuum pan and reboiled, 

 and this reboiling of the drainings is repeated two or three 

 times, with a gradually decreasing result in the quality and 

 quantity of the sugar. The last process, which is used to get rid 

 of the treacle, is a most beautiful one. The mass of sugar and 

 treacle is put into what are called " centrifugal pans," which are 

 drums about three feet in diameter and two feet high, which 

 make about 1000 revolutions a minute. These have false in- 

 teriors of wire gauze, and the mass is forced violently against 

 their sides by centrifugal action, and they let the treacle whirl 

 through, and retain the sugar crystals, which lie in a dry heap 

 in the centre. 



The cane is being flumed in with great rapidity, and the 



