V -METHOD OF PURIFYING THE RESIDUUM OF GAS-WORKS 

 BEFORE ALLOWING IT TO PASS OFF INTO THE WATER. 



By J. R. Shotwell.* 



Rahway, N. J., May 29, 1877. 



My Dear Sir : At our recent meeting in New York you requested me 

 to write you a description of the process by which the Rahway Gas-Light 

 Company eliminates the offensive and injurious portions of the residual 

 products resulting from the distillation of coal, in the manufacture of 

 gas, before allowing them to pass off into the river. Our works are on 

 the margin of a small stream, a branch of the Rahway River, whose 

 banks, for nearly a mile below the works, are occupied by residences, 

 and several streets cross it by bridges. To avoid the annoyance to the 

 community caused by the overflow from the tar-wells, we built supple- 

 mental wells to receive and hold the ammonia-water and light oils that 

 constitute the overflow. Valves with long rods reaching above the sur- 

 face were placed at the bottoms of these wells, and the men in charge of 

 the works were directed to open the valves after midnight so that the 

 offensive products might be carried off by the current before morning. 

 This plan did pretty well while the works were very small, but as the 

 quantity of gas made increased, the refuse necessarily increased also, 

 and complaints multiplied against our defilement of the waters. 



About two years since we adopted a plan, at the suggestion of Mr. 

 George W. Edge, of the Jersey City Gas-Light Company, of straining 

 the overflow through a mass of the finer particles of coke, technically 

 called " breeze," before allowing it to pass into the river. This has proved 

 completely successful. 



The accompanying drawings and descriptions will show the simple 

 and inexpensive method of accomplishing the very important result of 

 removing the deleterious matter from the ammonia-water before it is 

 allowed to flow into the river. We have one tar- well at the retort-house 

 and another at the purifying-house, each one having its supplemental 

 well. These wells have been adapted to the new process I have described 

 by merely dividing them by a horizontal partition, as shown in the draw- 

 ings. It will readily occur to any engineer of gas-works that the same 

 process could be carried out in various ways. 



One remarkable feature in our experience in this matter is that we 

 have never changed the breeze since it was first put in. We pump out 



* Commissioner of fisheries of the State of New Jersey and president of the Rahway 

 Gas-Light Company. 



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