228 ANNUAL OF SCIENTIFIC DISCOVERY. 



perfect than that of lamps and candles. In using the latter, there is a pre- 

 paratory process of vaporization a necessary part of the light-giving opera- 

 tion. In burning gas this is dispensed with, and many unpleasant odors are 

 thereby avoided. 



How happens it that a room once considered so comfortable when lighted 

 by candles, should "all at once become oppressively warm when lighted by 

 gas ? This is a question not very difficult to answer. It is an every-day 

 occurrence. In the room referred to on ordinary occasions, there had pro- 

 bably been two candles used. On special occasions, the number might have 

 been increased to four. Gas light is introduced. The usual habits of pru- 

 dence and economy in the use and management of light seem to be entirely 

 forgotten. Gas being much cheaper than candles, the light more agreeable, 

 and the quantity so easily increased, all the thoughts are absorbed in lighting 

 the room effectively. If only one gas-burner be used, and that perhaps may 

 not be the proper form and size adapted to the room it is likely that in the 

 first experiences of a good light, the quantity may be equal to that from eight, 

 or ten, or even twelve candles. If two burners instead of one be used, even 

 supposing them to be appropriate, and of a smaller size, it is not likely that 

 there will be less light than from eight or ten candles. 



In the case here described, is it wonderful that the room should be uncom- 

 fortably warm ? What is to be done ? Be more economical of light. Obtain 

 the advice of those whose knowledge and experience may be relied on, and, 

 following their directions, use suitable burners and glasses, admit a continuous 

 supply of fresh ah- to the room, and adopt some of the simplest and cheapest 

 methods of ventilation. All will then go on well. Every room and passage 

 in a house might be properly, that is, effectively lighted ; and there need be 

 no waste of gas, no excess of light, no uncomfortable degree of heat, and 

 what is likely to be of equal importance, no cause of complaint about expense. 

 These conditions imply good management ; by which is meant just the same 

 amount of care and watchfulness as are usually exercised over other domestic 

 arrangements. 



There is no reason why gas should be wasted, or used extravagantly, any 

 more than that the most ordinary articles of food, or clothing, or fuel, should 

 be thrown away or misapplied. This is a part of domestic management in 

 which servants require to be well instructed. Until it is explained to 

 them, it is difficult for some persons to understand how that which can be 

 seen only by its illuminating effects can so easily be lost, or improperly used, 

 or wilfully wasted. A few lessons on this subject will be very useful. 

 Masters and mistresses wih 1 increase their own knowledge, by thus endeavor- 

 ing to impart a little of that which ought to be possessed by other members 

 of their household. 



When it is said the cost of gas is equal only to one-seventh of that of 

 (mould) candles, be it remembered the comparative cost of the materials has 

 reference to equal quantities of light from each. To suppose that the light in 

 a room hitherto supplied by two candles, and afterwards by gas equal to 

 'twelve candlevS, would cost less in the latter case than in the former, would 

 be a very great mistake. Experience soon corrects these errors ; but it 



