10 



giving the joint a quarter turn it will come asunder. The put- 

 ting together and taking asunder will not take more than a very 

 few seconds. It is perfectly tight to air and steam. 



13. Model of a new method of Working the Valves of a Loco- 

 motive Engine, by R. and W. Hawthorn, Newcastle-upon-Tyne. 



BOILER. 



A Centre of Slide Rod. 



B. — Centre of Cylinder. 



The slider a is attached by a pin to the centi-e of the con- 

 necting rod, working in the frame h b, which gives to the frame 

 a reciprocating motion vertically from the connecting rod at 

 every revolution of the cranked axle. The upper arm of the 

 frame 6 6 is conected with the arm d, fixed on the same weigh- 

 bar as the double arm c, by which the motion is communicated 

 to the slide valve by the change rod e. g is the reversing weigh- 

 bar, having three arms, hi n fixed upon it. The arm h is moved 

 by the rod k, communicating with the reversing handle or lever 

 worked by the engineman. I is connected to the change rod e, 

 by the bar m, which by moving the reversing handle or lever 

 can be changed from one of those pins to the other at the ends 

 of the double arm c, and the engine made to go in either di- 

 rection required. 



The arm n has a box with a set screw for adjusting its 

 length, by which any angle in a few minutes can be given to the 

 frame h b, which is a very important part in this arrange- 



