57 



small amounts of sugar from the diffusion juice of the factory. They 

 have furnished the following report, which will be of interest to those 

 studying this part of the subject: 



DENSMORES' REPORT. 



The John F. Porter steam evaporator deserves special notice in this report. It can 

 be safely and economically employed by every manufacturer of sorghum sirup and 

 sugar. The line of operation employed in this evaporator is that of a shallow body 

 of juice having a continuous flow forward among and over the pipes of steam-heated 

 coils while being purified and concentrated. 



The evaporator is composed of two pans or compartments, each of which is pro- 

 vided with a coil of copper pipe. By reason of a peculiar but simple method of ap- 

 plying steam to these coils, the development and throwing out of scum and impurities 

 is begun as soon as the juice enters the evaporator, and is kept up until the juice ia 

 thoroughly purged of all impurity. The scum collects along one side of each pan, 

 and within an average distance of 8 inches from the point where it was developed, 

 and is removed from the pan as required by a simple and effective arrangement of 

 skimmers. 



While purification has been in progress the juice has been concentrated to a heavy 

 semi-sirup, which is then finished to the desired density. 



The line of operation is continuous aud uninterrupted, the juice being admitted to 

 and the finished product escaping from the evaporator in a continuous stream. 



During the month of September last one of the largest of these evaporators was set 

 up and operated at the Parkinson Sugar Works, Fort Scott, Kans., by the manufact- 

 urers for the purpose of investigating the adaptation of the principle therein em- 

 ployed to the manufacture of sugar, aud with special inquiry as to the per cent, or 

 amount of inversion of sugar which it might cause. 



Four runs or tests were made with this question in view, and the results given in 

 ratio of glucose to sucrose were as follows: 



Test No. 1. Juice 1 of glucose to 3.24 of sucrose. 



Finished product 1 " 3.05 " 



Test No. 2. Juice 1 " 3.29 " 



Finished product 1 " 3.27 " 



Test No. 3. Juice 1 " 3.35 " 



Finished product 1 " 3.36 " 



Test No. 4. Juice 1 " 3.60 " 



Finished product 1 " 3.53 " 



Deductions from these results show as follows : In the first test, a loss by inversion 

 of a little over 1 per cent. ; in the second and third tests there was practically no 

 loss, and in the fourth test a loss of less than a third of 1 per cent. The average loss 

 on the four tests was less than three-eighths of 1 per cent. Practically, this process 

 causes no inversion of the sucrose of the juices. 



To the wants of the sirup manufacturer, the Porter evaporator is fully adapted in 

 every essential and particular necessary to success. It works rapidly and produces a 

 sirup of bright color and best quality. It is easily operated, and the line of opera- 

 tion is wholly within the control of the operator, whether working for sirup or 

 sugar. 



Mr. A. A. Denton made some experiments in air evaporation at the 

 Sterling Sirup Works, and has furnished the following report of his 

 apparatus and operations : 



DENTON'S REPORT. 



The Sterling Sirup Works have made careful tests of two forms of air-evaporating 

 apparatus in manufacturing sirup this season, and believe the results are of impor- 



