Q. I was reading the other day of the different globes for gas-fixtures and their loss of diffusion, and it stated as follows: A plain glass globe they say loses 12 per cent., a ground glass globe 40 percent., and an opal porcelain glass globe 60 per cent. Please tell me if you think this is correct. The reason I ask for this explanation is, that I took four ground globes out of a parlor; the cause of so doing was, they did not give enough light, and I substituted four opal globes, and two of these lighted gives more light than the three of the ground globes, and the workings of the opal globes does not conform with opaque rules. Please tell me your opinion of the matter.

A. The amount of light absorbed by glass globes varies somewhat according to the nature of the glass. A plain glass globe absorbs from 10 to 15 per cent.; ground glass from 25 to 40 per cent., and opal, from 35 to 60 per cent. Determinations recently made with the globes now in common use, having large openings at the bottom and top, show that 26 per cent, of the light is absorbed by ground glass, and 55 per cent. by opal glass. One advantage of globes with large openings at the bottom is that some of the light escapes into the room through the opening, and if these globes were substituted for the old-fashioned ones with small openings, considerable would be gained. Aside from this, globes having small openings cause a flickering and smoky flame, by-producing strong currents of air through the globe.