APPENDIX 



TO 



THE FOURTH EDITION 



By RUSSELL S. WRIGHT 



IT is desirable to add to this fourth edition a few particulars of 

 new apparatus and other details which have been designed or 

 improved since the last edition was published in 1895. 



Oil lamps. Petroleum-oil lamps have been very considerably 

 improved during the last few years by all the leading makers. 

 The main lines of improvement have been the same in all, and 

 have consisted in greatly increasing the height of the chimney 

 providing more ample access to the flames, and fitting a larger and 

 more easily adjustable reflector at the back. Fig. 233, representing 

 Messrs. Newton's lamp, illustrates these points, especially the first. 

 The bottom portion alone of the chimney is here nearly as high as 

 in the older forms. The lamp is to be first lit and burnt for two 

 or three minutes with this portion only in position, then the 

 upper portion of the chimney is added and the flames regulated, 

 the enlarged reflector being also adjusted if required. This method 

 of getting up the draught applies in principle to all the improved 

 lamps. 



In Stock's pattern the chimney is raised (after lighting) by a 

 rack and pinion, but I am not able to trace any benefit from this 

 additional complication. With some of these improved four- wick 

 lamps 120 or 130 candle power can be obtained with a whiter light 

 than formerly, which is sufficient to illuminate a 12-ft. disc well. 



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