xiv INTRODUCTION. 



Late Improvements. 



It will be seen, by examining the triple-jet as now made, 

 that it has been improved since the illustrating cuts were 

 drawn, by plating it completely with metal, to prevent 

 burning, in case a piece of hot lime falls upon it ; by the 

 clamp operated at the side of the lantern body, to fix it 

 firmly in position when adjusted; by an easier working 

 screw in a more convenient position for regulating the 

 height, and which will lower the jet so it will slide under 

 the flame chamber of the Oil-light Sciopticon ; by the 

 backward inclination of the jet tubes so as to strike more in 

 front of the lime; by giving the mixed jet a conical 

 shape, and tipping it with a gun nipple or platina ; by 

 using a lime holder for the alcohol burner, which is held 

 by its sliding over the alcohol tube, utilizing its heat in 

 vaporizing the alcohol ; by a roller attached to the latch of 

 the winker, and a thumb-screw at its lower bearing, to ease 

 and moderate its movement; by a chimney which more 

 completely shuts in the light without preventing the escape 

 of heat ; by a hand-wrench which tightens or unscrews the 

 outer *ube by its half-round end, and works the oxygen 

 tube and nipple with the other ; by using a shorter holder 

 and a larger lime (two and a half inches in diameter) for 

 the gas lantern ; and by an improved spring in the slide 

 carrier. 



Though we often indulge in reforming our apparatus, as 

 has just been shown, we do not recommend the practice to 

 purchasers at the first start. There is a tendency among 

 experts in familiar styles to modify what is new into what 

 is more in accordance with preconceived notions ; so this 

 apparatus sometimes gets twisted till it is not like itself, 

 nor like anything else, either. For example, the goose- 

 neck jet, which is a familiar form, and very good in its 



