 ... lamp 20 hours, but if the lamps are of the same kind the cost will be about the same. Calculations of the cost of producing 1000 candle-hours by different lamps are sometimes useful in choosing between lamps, but, of course, it does not necessarily...  Measurements for the Household - Side 34av Massachusetts. Department of Weights and Measures - 1917 - 53 siderUten tilgangsbegrensning - Om denne boken
 | 1915 - 854 sider
...1000 candle-hours of lighting may be obtained by burning a lo-candle lamp 100 hours or a 5o-candle lamp 20 hours, but if the lamps are of the same kind...about the same. Calculations of the cost of producing 1000 candle-hours by different lamps are sometimes useful in choosing between lamps, but of course... | |
 | United States. National Bureau of Standards - 1917 - 272 sider
...candle-hours of lighting may be obtained by burning a zo-candlepower lamp 100 hours or a 5o-candle power lamp 20 hours, but if the lamps are of the same kind...about the same. Calculations of the cost of producing 1000 candle-hours by different lamps are sometimes useful in choosing between lamps, but, of course,... | |
 | 1917 - 594 sider
...lo-candlepower lamp 100 hours or a 5o-candle power lamp 20 hours, but if the lamps are of the same kird the cost will be about the same. Calculations of the cost of producing 1000 candle-hours by different lamps are sometimes useful in choosing between lamps, but, of course,... | |
 | Martha Van Rensselaer, Flora Rose, Helen Canon - 1919 - 752 sider
...burned by the number of hours they burn. For example, 1,000 candle-hours of lighting may be obtained by burning a 10-candle lamp 100 hours or a 50candle...of the same kind the cost will be about the same. Caleulations of the cost of producing 1,000 candle-hours by different lamps are sometimes useful in... | |
 | William D. Henderson - 1921 - 590 sider
...lamps used by the number of hours they burn. For example, 1000 candlehours of lighting may be obtained by burning a 10-candle lamp 100 hours or a 50-candle...about the same. Calculations of the cost of producing 1000 candle-hours by different lamps are sometimes useful in choosing between lamps, but of course... | |
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