﻿2 Prof. Silliman on the Examination of the Bessemer Flame 



mistakable as to render its use safe in the most inexperienced 

 hands. 



The following experiments were made at the Bessemer Steel 

 Works of John A. Griswold and Co., in Troy, while pursuing 

 the chemical course in the Winslow Laboratory of the Rensselaer 

 Polytechnic Institute. In my observations on the flame, I made 

 use of the spectroscope and also of a combination of coloured 

 glasses. This combination consisted of two light-yellow glasses 

 and a blue one, through which the sunlight appeared of a deep 

 purplish-blue tint ; and as it differed slightly from Rowan's, it 

 gave somewhat different results. 



In order to reproduce the appearance of the flame at the dif- 

 ferent stages of the process, I prepared a plate consisting of 

 about a hundred varieties of colours and tints, all of which were 

 numbered, and thus referred to a Table which indicated their 

 composition. They were also arranged to be seen with either a 

 light or dark background. The use of this plate was of neces- 

 sity limited to daylight ; but the illustration and description are 

 given as occurring at night in order to show its illuminating- 

 power. 



At the beginning of the process that which issues from the 

 converter does not appear to be a true flame, but only an illu- 

 mined stream of gas carrying with it innumerable red-hot pellets 

 of iron. This gas has scarcely any illuminating-power, extends 

 but a short distance from the mouth of the converter, and is 

 sometimes sheathed with a whitish smoke. Seen through the 

 glasses, the flame and sparks have a deep crimson colour, the 

 converter is invisible, and at the base of the flame is a crimson 

 band which continues throughout the process. 



As the reaction continues > this stream of gas grows brighter 

 and more elongated, and after a few minutes a small pointed 

 whitish flame appears which suddenly increases in size. At 

 this instant the blast-pressure falls from twenty to eighteen 

 pounds. 



When viewed through the glasses, the upper part of the con- 

 verter comes dimly into view, and the flame and pellets of iron 

 appear of a lighter colour, while the fragments of slag which 

 begin to be thrown out are of a deep red. This difference in 

 shade between the iron and slag thrown out is probably entirely 

 owing to the lower temperature of the latter — for the reason that, 

 while the iron is discharged from the metallic bath, the slag is 

 washed up on the sides of the converter, and can be seen cling- 

 ing around its mouth in a spongy mass until detached and 

 thrown out by the blast. The greater porosity of the slag and 

 its consequent more rapid cooling would also cause a difference 

 of temperature. 



