NEGRETTI AND ZAMBRA'S 

 INVENTIONS AND IMPROVEMENTS. 



1. Enamelling the centre or back of Thermometer Tubes. By this invention, Negretti 

 and Zambra have been enabled to make Thermometers at least twenty times 

 more sensitive than heretofore. The delicate Clinical Thermometers now so 

 extensively used could never have been efficiently constructed without the aid 

 of the enamelled tube. See Sensitive Thermometers, pages 32 and 160. 



2. Negretti and Zambra's Patent Self-Registering Maximum Thermometer. Pp. 36 

 to 45. For a Report on the value of this Thermometer by the Kew Committee 

 see pages 37 and 38. 



3. The Application of Porcelain and Enamelled White Glass Scales to Barometers 

 and Thermometers, the divisions being permanently etclied or painted thereon ; 

 a plan now universally adopted by all makers. 



4. Negretti and Zambra's Patent Mercurial Minimum Thermometers (two patents). 

 See pages 47 to 50. 



5. Negretti and Zambra's Patent Self -Registering Maximum Thermometer, specially 

 arranged for obtaining underground temperatures, Mines, Springs, &c., Marine 

 service, Solar Observations, &c., &c. Seepages 42, 44, 145, 171, and 172. 



6. FitzRoy's Marine Gun Barometer, constructed for use in Her Majesty's Navy, by 

 Negretti and Zambra, the only one adopted and in use in Her Majesty's vessels. 

 See pages 11 and 12. 



7. FitzRoy's Storm or Life-Boat Service Barometer. See page 143. 



8. Pocket and Watch- sized Aneroid Barometer. The first Pocket Aneroid ever produced 

 was manufactured by Negretti and Zambra for the late Admiral FitzRoy. 

 See pages 24 to 27. 



9. The Double Bulb Deep Sea Thermometer, first constructed and supplied to Her 

 Majesty's Navy by Negretti and Zambra in 1 862. For full particulars and the 

 history of this important invention see pages 63, 64, 65, and 173. 



10. Improved Standard Mercurial Deep-Sea Thermometer, the only Instrument capable 

 of giving correct temperatures of the bottom or any intermediate depth of the 

 sea. See pages 66 and 67. 



11- Negretti and Zambra's Patent Strengthened Glass Hydrometer. Seepage 194. 

 12. A Portable form of the Open Range Glycerine Barometer. See page 18. 



13. Self Recording Aneroid Barometers with various Improvements. 



See pages 27 and 28. 



14. Improved Self-Recording Barographs, Thermographs, Hygrometers. 



Seepages 30, 53 to 56, 130. 



15- Negretti and Zambra's Patent Apparatus for recording Hourly Temperatures. 



Seepages 55 and 78. 



16. Recording Anemometers, Electrical. Various arrangements constructed by 

 Negretti and Zambra. 



