HI. CALORIMETRY. 231 



1081. Bailey's Patent Baker's Pyrometer, " Baker's 

 Guide," for ascertaining the temperature of bakers' ovens, and 

 enabling them to prevent the possibility of the bread becoming 

 burnt, by keeping the oven at one uniform temperature. 



W. H. Bailey $ Co. 



1082. Wood and Bailey's Patent Blast Furnace Pyro- 

 meter, for ascertaining the temperature of hot blasts. 



W. H. Bailey S>- Co. 



lO82a. Photograph of M. Guyeau's Apparatus for 

 determining the Coefficients of Dilatation. 



M. Laurent, Paris. 



1082b. Microgoniometer. An instrument for measuring 

 the expansion of metals by heat. Prof. Dr. F. Pfaff. 



III.CALORIMETKY. 



1057. Apparatus employed by Dr. Andrews in his experiments 

 on the amount of heat disengaged in the combination of hydrogen 

 and other combustible gases with oxygen. Dr. Andrews, F.R.S. 



The gases contained in a cylindrical vessel of thin copper are exploded by 

 the ignition of a fine platinum wire, and the heat is measured by the rise of 

 temperature of the water in a calorimeter, capable of being rotated gently 

 round its horizontal axis. 



1058. Apparatus for determining the amount of heat produced 

 in the combination of liquids and solids with oxygen. 



Dr. Andrews, F.R.S. 



1060. Thermometric Tube for determining the calorific capa- 

 cities of different liquids. Elie Wartmann, Geneva. 



A thermometric tube, being part of the contributor's apparatus for the 

 determination of calorific capacities in liquids. A full description of the 

 method is printed in the number for May 1870 of the " Archives des Sciences 

 physiques et naturelles." An electric chronoscope, such as Sir Charles 

 Wheatstone's, expresses in thousandth parts of a second the time necessary 

 for the cooling between two constant temperatures of the same body (the ther- 

 mometric tube) when immersed in equal volumes of different liquids, at the 

 game initial degree of heat. 



1061. Apparatus made by De la Hive and Marcet for 

 measuring the specific heat of Gases. A small copper calori- 

 meter, containing a very thin serpentine gold pipe. 



Lucien de la Rive, Geneva. 



1O63. Drawing of an Apparatus for determining the calo- 

 rific capacity of liquid substances. 



Dr. Leopold Pfaundler, Professor of Physics at Innsbruck. 



