Light, 192,000 miles per second.

Electricity, 288,000 miles per second.

QUANTITY OF OIL REQUIRED FOR DIFFERENT COLORS.

Heath & Miligan quote the following figures.  They are color manufacturers: 

100 parts (weight) White Lead require 12 parts of oil. 100 parts (weight) Zinc White require 14 parts of oil. 100 parts (weight) Green Chrome require 15 parts of oil. 100 parts (weight) Chrome Yellow require 19 parts of oil. 100 parts (weight) Vermilion require 25 parts of oil. 100 parts (weight) Light Red require 31 parts of oil. 100 parts (weight) Madder Lake require 62 parts of oil. 100 parts (weight) Yellow Ochre require 66 parts of oil. 100 parts (weight) Light Ochre require 72 parts of oil. 100 parts (weight) Camels Brown require 75 parts of oil. 100 parts (weight) Brown Manganese require 87 parts of oil. 100 parts (weight) Terre Verte require 100 parts of oil. 100 parts (weight) Parisian Blue require 106 parts of oil. 100 parts (weight) Burnt Terreverte require 112 parts of oil. 100 parts (weight) Berlin Blue require 112 parts of oil. 100 parts (weight) Ivory Black require 112 parts of oil. 100 parts (weight) Cobalt require 125 parts of oil. 100 parts (weight) Florentine Brown require 150 parts of oil. 100 parts (weight) Burnt Terra Sienna require 181 parts of oil. 100 parts (weight) Raw Terra Sienna require 140 parts of oil.

According to this table, a hundred parts of the quick drying white lead are ground with 12 parts of oil, and on the other hand slow drying ivory black requires 112 parts of oil.

PAINTING.

1 gallon Priming Color will cover 50 superficial yards. 1 gallon White Zinc will cover 50 superficial yards. 1 gallon White Paint will cover 44 superficial yards. 1 gallon Lead Color will cover 50 superficial yards. 1 gallon Black Paint will cover 50 superficial yards. 1 gallon Stone Color will cover 44 superficial yards. 1 gallon Yellow Paint will cover 44 superficial yards. 1 gallon Blue Color will cover 45 superficial yards. 1 gallon Green Paint will cover 45 superficial yards. 1 gallon Bright Emerald Green will cover 25 superficial yards. 1 gallon Bronze Green will cover 45 superficial yards.

One pound of paint will cover about four superficial yards the first coat, and about six yards each additional coat.

RAPID PROCESS OF MARKING GOODS AT ANY DESIRED PER CENT.  PROFIT.

Retail merchants, in buying goods by wholesale, buy a great many articles by the dozen, such as boots and shoes, hats and caps, and notions of various kinds; now the merchant, in buying, for instance, a dozen hats, knows exactly what one of these hats will retail for in the market where he deals; and unless he is a good accountant, it will often take him some time to determine whether he can afford to purchase the