13 



Telegraph. — No. 1, shows the position of the two arms for day 

 signals. No. 2, shows the position of the lamps for night signals. 

 No. 3, shows the arrangement for effecting the night signals. 



24. Model of a Self Acting Fire Alarm. — Constructed on the 

 principle of the expansion of metals by heat, acting on compound 

 levers and disengaging a spring, which sets off a bell. 



25. Model of a Self-acting Ventilator. — Founded on the same 

 principles as the above Fire Alarm, but in this a door or 

 aperture is opened or shut by the application of heat. 



26. Model of an Improved Mode of Ship-building, and of a 

 new Safety Keel, — By Oliver Laing, Esq. Woolwich. 



27. Model of a Machine for pumping Vessels and extinguish- 

 ing Fires on Shipboard. — By J. Dalziel, M.D. — The moving 

 power of this machine is derived from the action of the water 

 on paddle wheels, when the vessel is under way. 



28. Model of Railway formed on continuous Blocks of Stone. 



29. Model of Steam Boiler Copper. 



30. Ditto, Ditto. 



31. Ditto, Ditto. Wood. 



By Joseph Price, Esq. Gateshead. 



32. Model of a Patent Wind/ass. — By George Straker. 



33. Model of a Force Pump. — By John Lightfoot. 



34. Improved Articulated Stethescope. — By Dr. Granville. 



35. Model of an Apparatus for promoting Artificial Respira- 

 tion.— By J. Dalziel, M.D. 



36. Gas Meter. — By Crossley, with transparent cut back and 

 front, shewing its action. 



37. Working Model of another Gas Meter. — By Crossley, 

 with three transparent chambers attached to a gas holder. 



38. Telescope exhibiting a new method of Mounting. — By C. 

 Garbutt, Gateshead. 



39. Mode of applying the Common Level to the purposes of the 

 Transit Instrument. — By the Rev. N. S. Heineken, Sidmouth. 

 The object of this model is to show the application of the com- 

 mon Y level, slightly altered, to the purposes of the transit in- 

 strument, so that anv clockmaker may construct for himself an 



