IX. MISCELLANEOUS. 459 



2209. Historical Series of published engravings, showing 

 the improvements in lighthouse illumination between 1787 and 

 1876, by the Engineers of the Northern Lighthouse Board. 



Messrs. D. and T. Stevenson. 



2210. Example of French Lighthouses. 



Lighthouse Service of France. 



221Oa. Polygonal and Annular Lenses. Apparatus for 

 fixed light and for annular reflection ; Arago and Fresnel's four- 

 wick burner, two with burner of Henry Lepaute, &c. 



Department of Lighthouses, France. 



VIII. MI SCELLANEOUS. 



2210b. Model of Tumbler Lock and Key. 



Council of King's College, London. 



2210c. Model of Ancient Egyptian Lock and Key. 



Council of King 's College, London. 



221Od. Model of Mangle Motion. 



Council of King's College, London. 



2211. Steam Engine. Tangye's (Willan's Patent) three-inch 

 three cylinder steanr engine with vertical boiler, feed pump for 

 same, and all fittings complete, on one base plate. 



Tangye Brothers and Holman. 



This engine is of the simplest construction possible ; it is self-contained, 

 has neither eccentrics, separate slide valves, nor piston rod guides, and can be 

 driven at a very high rate of speed without the slightest noise. 



2212. Steam Engine. 6-horse power expansion portable 

 steam engine, fitted with Head and Schmidt's patent straw burning 

 apparatus and patent automatic governor expansion gear. 



Ransomes, Sims, and Head. 



By means of this patent invention all kinds of vegetable substances can 

 now be used as fuel in a portable steam engine, such as straw, reeds, dry 

 grass, cotton and maize stalks, brushwood, &c., and by removing the patent 

 apparatus the engine can also be fired with wood or coal in the ordinary 

 manner. 



This engine is also fitted with a separate expansion slide valve, and Brown's 

 patent automatic governor expansion gear, which consists of a link motion 

 attached direct to the expansion valve, and under the control of the governor, 

 by means of which the amount of steam admitted into the cylinder is varied 

 instantaneously in exact proportion to the work to be performed by the engine j 

 an arrangement of the utmost importance in all cases where the load on the 

 engine is suddenly increased or diminished, or where exact regularity of 

 motion in the machine which is being driven is essential to success. The 

 engine has also a simple and efficient arrangement for heating the feed water 

 by means of the exhaust steam, and is provided with two safety valves, steam 

 pressure guage, and all the most modern and complete fittings and accessories. 



