III. MISCELLANEOUS. 615 



3021. Six's Thermometer. Miller pattern ; bulb protected 

 as proposed by Dr. Miller. Casella; date 1869. In use in 

 H.M.S. " Challenger :" generally adopted, after being tested to 

 three tons on the square inch. 



The full bulb is protected by an outer glass casing. The errors of these 

 thermometers are determined under pressure, and are found to be reduced to 

 the limits of about 1-2 for depths of 2,500 or 3,000 fathoms. 



Two protected bulb thermometers which were broken by pressure at a 

 depth of 3,875 fathoms in the Atlantic Ocean. 



3022. Johnson's Metallic Self-registering Thermo- 

 meter. Invented by Mr. Henry Johnson (about 1858). Not in 

 general use. 



3023. Saxton's Metallic Self-registering Thermometer 



(about 1855). Used on the United States Coast Survey. Not in 

 general use. 



3024. Water Bottle. In ordinary use for bringing up water 

 from ocean depths. [Superseded in H.M.S. "Challenger" by 

 Buchanan's design.] 



3025. Water Bottle. Buchanan's ; date 1872. A drawing. 

 Invented by Mr. Buchanan, one of the scientific civilian staff 

 attached to " Challenger." 



3026. Barometer, Diagonal (about 1750). Watkins and 

 Smith, London. 



302 6 a. Barometer with Thermometer. 



Paul Greiner, Hamburg. 



The baro-thermometer, an instrument for measuring the depth of the sea, 

 is also intended for recording the temperatures and the salinity of the sea 

 water. 



III. MISCELLANEOUS. 



ROYAL GEOGRAPHICAL SOCIETY OF LONDON. 



3027. Instruments used by the late Dr. Livingstone in his 



last journey. The Royal Geographical Society of London. 



A pocket chronometer, by Jas. McCabe, 194, Royal Exchange, London. 

 A sextant, by John Dalton, of Hartlepool. 

 Hypsometrical boiling apparatus, by Casella. 

 2 boiling point thermometers, by Casella. 

 1 ordinary thermometer, by Casella. 



3028. Instruments invented by Staff-Commander C. George, 

 R.N., Curator of maps and instruments to Royal Geographical 

 Society. Made by Mr. H. Porter (late Cary), optician, London. 



