Dr Fyfe on the Illuminating power of Coal and Oil Gas . 371 
7.8, that is, 1 to 1.2. And, taking them burning under the 
least favourable circumstances, it is as 3.84 to 6.78, that is, 1 
to 1.7. Taking the coal-gas under the least advantageous, and 
oil-gas under the most advantageous circumstances, the illumi- 
nating is as 8.8 to 7, or as 1 to 2,03. 
These experiments were repeated on another night, with the 
same gases. 
Coal-Gas.-— Exp. 6.-— Argand, No. 1. consumed 1.79 feet per 
hour, with 3 inch flame, and gave a light equal to that of 7.2 
candles, that is, 1 foot to 4.02 candles. 
Exp. 7. — Argand, No. 2. consumpt 3 feet, light equal to 13 
candles, that is, 1 foot equal to 4.33. 
Oil-Gas. — Exp. 8.-— Argand, No. 1. consumed, with 1J inch 
flame, 1.46 feet, light equal 6.2 candles, that is, 1 foot equal to 
4.24. 
Exp. 9-— -Argand, No. 2. consumpt per hour 2 feet ; light 
equal to 11.3 candles, or 1 foot equal to 5.64. 
Exp. 10. — Argand, No. 1. (of Glasgow) consumed 1.36 feet 
per hour, flame 2J inches ; light equal to 8.1 candles, or 1 foot 
equal to 5.95. 
The conclusion from these trials, taking each gas under the 
most favourable circumstances, is as 4.33 to 5.95, that is, 1 to 
1.37. 
Taking them under the least advantageous, it is as 4.02 to 
4.24, or 1 to 1.05. 
Taking the coal-gas under the least, and oil-gas under the 
most favourable circumstances, it is as 4.02 to 5.95, that is, 1 
to 1.48. 
The above trials give the illuminating power as follows : 
Experiments. 
Burner. 
Coal-Gas. 
Oil-Gas. 
1. and 3. 
1 
1 
1.7 
1. — 5. 
1 
1 
1.8 
2. — 4. 
2 
1 
1.18 
0. — 8. 
1 
1 
1.05 
6. — 10. 
1 
1 
1.48 
7. — 9. 
2 
1 
1.3 
6.)8.51 
Giving an average of Coal-Gas 1, 
Oil-Gas » 
1.42 
a a 2 
