20 



80. Magneto-electric machine, by Ladd. 



Lent by the Biological Laboratory, Royal College of 

 Science. 1878. 



This is an old pattern, formerly used for medical purposes. 

 The horse -shoe magnet is in the form of an almost complete 

 circle and the coils revolve between its poles. 



81. Spectroscope, by Browning. 



Lent by the Biological Laboratory, Royal College of 

 Science. 1878. 



The instrument has two prisms mounted on an 8-inch 

 graduated circle. 



82. Thermometers by various makers and graduated 

 in different ways to serve a variety of purposes. 



I. Made by Geissler and Son, Berlin. 



Thermometer graduated on Prof. Virchow's plan. The 



range is from to 50 C. ; each degree divided into 



tenths. E. 242. 1877. 

 Thermometer graduated on Prof. Haidenhain's plan. The 



range is from 28 to 46 C. E. 243. 1877. 

 Thermometer with a broad flat bulb for determining the 



temperature of the skin. Graduated to tenths of a 



degree. E. 244. 1877. 

 Thermometer for determining the temperature of the ear. 



E. 245. 1877. 



II. Made by W. Haak, Neuhaus, Thuringen. 



Two thermometers graduated on Prof. Virchow's plan. 



E. 96, 97. 1877. 

 Two thermometers devised by Dr. Traube for medical use. 



The range is from 23 C. in one case, 26 C. in the other, 



to 46 C., and each degree is divided into tenths. E. 106, 



107. 1877. 



III. Designed and presented by M. Immisch. 



A small thermometer in circular metal case. The changes 

 in temperature affect the form of a small closed curved 

 tube, which moves a needle round an index. The instru- 

 ment is intended for ascertaining the temperature of the 

 human body. E. 117. 1886. 



A similar instrument from which the face has been r* moved 

 to show the internal structure. E. 118. 1886. 



