 | Edward Charles Frome - 1840 - 232 pages
...of an inch in diameter, placed in the focus of a parabolic reflector, and raised to an intense heat by a stream of oxygen gas directed through a flame of alcohol, produced a light eighty times as intense as that given by an argand burner. A station on the hill,... | |
 | Edward Charles Frome - 1850 - 292 pages
...of an inch in diameter, placed in the focus of a parabolic reflector, and raised to an intense heat by a stream of oxygen gas directed through a flame of alcohol, produced a light eighty times as intense as that given by an argand burner. A station on the hill in... | |
 | Sir Henry Edward Landor Thuillier - 1851 - 826 pages
...of an inch in diameter, placed in the focus of a parabolic reflector, and raised to an intense heat by a stream of oxygen gas directed through a flame of alcohol, produces a light eighty times as intense as that given by an Argand burner, and is visible even in... | |
 | William Mitchell Gillespie - 1869 - 550 pages
...truncated cone of burnished tin will reflect the sun's rays to the eye in almost every situation. Eut a " heliotrope," which is a piece- of looking-glass, so...produced by a stream of oxygen gas directed through aflame of alcohol upon a ball of lime. Its distinctness is exceedingly increased by a parabolic reflector... | |
 | William Mitchell Gillespie - 1875 - 530 pages
...burnished tin will reflect the sun's rays to the eye in almost every situation. But a "heliotrope/5 which is a piece of looking-glass, so adjusted as...signals, an Argand lamp is used ; or, best of all, Drummend's light, produced by a stream of oxygen gas directed through a flame of alcohol upon a ball... | |
 | 1878 - 534 pages
...truncated cone of burnished tin will reflect the sun's rays to the eye in almost every situation. But a " heliotrope," which is a piece of looking-glass, so adjusted as to reflect the slin directly to any desired point, is the most perfect arrangement. For night signals, an Argand lamp... | |
 | William Mitchell Gillespie - 1880 - 540 pages
...truncated cone of burnished tin will reflect the sun's rays to the eye in almost every situation. But a " heliotrope," which is a piece of looking.glass, so...signals, an Argand lamp is used ; or, best of all, Drum. mond's light, produced by a stream of oxygen gas directed through a flame of alcohol upon a ball... | |
 | 1896 - 966 pages
...consisted of a ball of lime, placed in the focus of a parabolic reflector, and raised to an intense heat by a stream of oxygen gas directed through a flame of alcohol. The brightness of this light was so intense that on one occasion it rendered the station at Slieve... | |
 | John Whitelaw - 1902 - 638 pages
...lime about \ in. diameter placed in the focus of a parabolic reflector and raised to an intense heat by a stream of oxygen gas directed through a flame of alcohol. This produces a light eighty times the intensity of an Argand burner. In boisterous and hazy weather... | |
 | 1911 - 338 pages
...placed in the focus of a parabolic reflector, and raised to an intense FIG. 109. FTG 110. FIG. III. heat by a stream of oxygen gas directed through a flame of alcohol, produces a light eighty times as intense as that given by an Argand burner, and is visible even in... | |
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heliotrope," which is a piece of looking-glass, so adjusted as to reflect the sun directly to any desired point, is the most perfect arrangement. For night signals, an Argand lamp is used ; or, best of all, Drummond's light, produced by a stream of oxygen... 