For a table of the relative laminability of metals, see DUCTILITY.
LAMIUM ALBUM, or the dead nettle, is said by Leuchs to afford in its
leaves a greenish-yellow dye. The L. purpureum dyes a reddish-grey with
salt of tin, and a greenish tint with iron liquor.
LAMPS differ so much in principle, form, and construction, as to render
their description impossible, as a general subject of manufacture. In
fact, the operations of the lampist, like those of the blacksmith,
cabinet-maker, cooper, coppersmith, tinman, turner, &c., belong to a
treatise upon handicraft trades. I shall here, however, introduce a
tabular view of the relative light and economy of the lamps most
generally known.
+----------+----------------------------------+------+------+-------+
| Kind | Intensity of light during | Mean |Con- | Light |
| of +----+-----+-----+-----+-----+-----+ of 7 |sump- | from |
| Lamps. | 1 | 2 | 3 | 4 | 5 | 6 |hours.|tion | 100 |
| |hour|hours|hours|hours|hours|hours| |per | parts |
| | | | | | | | |hour |of oil.|
| | | | | | | | |in | |
| | | | | | | | |gram- | |
| | | | | | | | |mes. | |
+----------+----+-----+-----+-----+-----+-----+------+------+-------+
|Mechanical| | | | | | | | | |
|lamp of | | | | | | | | | |
|Carcel | | | | | | |100 |42 | 238 |
|Fountain | | | | | | | | | |
|lamp, and | | | | | | | | | |
|a chimney | | | | | | | | | |
|with flat | | | | | | | | | |
|wick |100 | 98 | 98 | 97 | 96 | 96 |125 |11 | 113 |
|Dome ar- | | | | | | | | | |
|gand |103 | 90 | 72 | 61 | 42 | 34 | 31 |26·714| 116 |
|Sinumbra | | | | | | | | | |
|lamp |102 | 95 | 83 | 81 | 78 | 66 | 56 |37·145| 150 |
|Do. with | | | | | | | | | |
|fountain | | | | | | | | | |
|above |100 | 90 | 70 | 52 | 41 | 32 | 85 |43 | 197 |
|Do. with | | | | | | | | | |
|another | | | | | | | | | |
|beak |100 | 97 | 95 | 92 | 89 | 86 | 41 |18 | 227 |
|Girard’s | | | | | | | | | |
|hydro- | | | | | | | | | |
|static | | | | | | | | | |
|lamp |101 | 96 | 84 | 81 | 76 | 70 | 63·66|34·714| 182 |
|Thilo- | | | | | | | | | |
|rier’s or | | | | | | | | | |
|Parker’s | | | | | | | | | |
|do. lamp |106 | 103 | 100 | 94 | 92 | 90 |107·66|51·143| 215 |
+----------+----+-----+-----+-----+-----+-----+------+------+-------+
In the above table, for the purpose of comparing the successive degrees
of intensity, 100 represents the mean intensity of light during the
first hour. The quantity of oil consumed per hour is given in grammes,
of 15-1/2 grains each. The last column expresses the quantity of light
produced with a like consumption of oil, which was in all cases 100
grammes. See CANDLES.