Part 1 — Comparison of British and French Weights and Measures.

WEIGHTS AND MEASURES.

WEIGHTS.

Grain, Apothecaries' = 0·0648 grammes, French.

Ounce " = 31·102 "

" Avoirdupois = 28·346 "

Drachm, Apothecaries' = 3·888 "

Gramme = 15·4310 grains, Apoth.

Decigramme = 1·5434 " "

Centigramme = 0·1543 " "

MEASURES OF CAPACITY.

Cubic Inches. Fluid Ounces.

Litre = 61·028 = 35·79

Decilitre = 6·02 = 3·57

Centilitre = 0·610 = 0·35

Millilitre = 0·061 = 0·03

Lb. Oz.

Killogramme = 2 3¼ Avoirdupois.

MEASURES OF LENGTH.

Metre = 39·37 inches.

Decimetre = 3·93 "

Centimetre = 0·39 "

Millimetre = 0·03 "

Cubic inch of water at 32° = 252·45 grains.

" " mercury " = 3425·35 "

Fluid oz. of water = 437·50 "

" " measures = 1·73 cub. in.

1 f. drachm = 54·68 grains.

1 pint (New York) = 27·68 cub. in.

1 oz. bromine = 2½ f. drachms.

1 grain, Troy or Apoth. = 1·097 gr. Avoir.

1 lb. Avoir. = 7000 Troy grs.

1 " = 7680 of its own grs.

The drachm Avoirdupois is never used except in weighing silk.

Pendulum vibrating seconds at New York = 39·102 inches.

In weighing solids, few weights are really necessary if they are properly assorted; nothing less than half a grain is likely to be useful, and the series following will weigh any quantity from the half grain to two thousand one hundred and ten and a half grains, by differences of only a single grain.

The numbers are in grains, but the same principle may be carried out with any other denomination, whether ounces, pounds, or tons.

½, 1, 2, 3, 4, 10, 20, 30, 40, 100, 200, 300, 400, 1000, &c.

The artist should be provided with not less than three glass measures—one of a pint, graduated to ounces—one of two ounces, graduated to drachms—and one of two drachms, graduated to minims.

Lewis's Patent Glass Baths for Nitrate of Silver Solutions.—Since the foregoing pages have been in print this new article of Baths has been introduced, and will probably supersede all others now in market. They are encased in a box made expressly to hold them, and form a valuable and important improvement in the apparatus used in the various Glass processes.