Zi DENSITY OF SMOKE METHOD ON U. S. S. CONYNGHAM. 
for cleaning the face of pane nearest the stack, if found necessary; 7 designates 
a brass pipe leading from boiler room through box 3 and to the stack and whose 
function is to provide a steady stream of forced draft air through box 3 and stack, 
and thereby keep box 3 free from an accumulation of soot. 
Box 8 is provided with a slidable sleeve whose function is to vary the focal dis- 
tance of incandescent lamp 10 and lens 11. Means are provided on box 8 for lock- 
ing the sleeve in place after the focal distance has been determined. The lens, 11, 
is rigidly secured to box 8 and means are provided on box 8 for cleaning the lens 
if found necessary. No. 12 designates a pipe similar to pipe 7, and serves a similar 
purpose for box 8. 
No. 13 designates a metal plate installed in boiler room, in a location readily 
observable by attendants. On the plate (13) is installed the smoke indicating 
meter, 15, whose scale is arranged in accordance with Plate 2. 
No. 14 designates a potentiometer also installed on the plate, 13. The poten- 
tiometer is provided with a slidable brush 18 for adjusting the potential on the 
selenium plate 5, and serves as a simple and effective means for setting the indi- 
cator on the clear indication, as when no smoke is issuing from stack. No. 16 desig- 
nates a switch rigidly secured to plate 13, but insulated from it, and serves as a 
means of circuit control to potentiometer 14, meter 15, and selenium plate 5. No. 
17 designates a switch similar to switch 16, and for control of incandescent lamp 10. 
The system is connected, as shown, to the ship’s lighting battle main at 125 
volts. 
The following general advantages are claimed for the system :— 
(a) Making it possible for attendants in boiler rooms to observe directly the 
character of smoke issuing from stack and enabling them to adjust the amount of 
fuel and air necessary for perfect combustion. 
(b) Prevention of soot deposition on heating surfaces, such soot impairing 
the evaporative efficiency. 
(c) Informs firemen of smoking condition of stacks and serves as a means 
for elimination of the many objections to same. 
(d) Elimination of personal error from a naval strategical standpoint in de- 
termining smoke densities. At present the recording of smoke densities is depen- 
dent on the human vision in comparison to arbitrary shades and colors. 
DISCUSSION. 
Tue Present :—Is there any discussion on the paper which has just been read en- 
titled, ‘““New Method of Indicating the Density of Smoke as Installed on the U. S. S. 
Conyngham?” We will be glad to hear from any member who has any views to express on 
this new method of indicating the density of smoke. 
