972 



SEC. 18. BIOLOGY. 



8. Explorator for determining the changes in the, size of the 

 hand. 



8a. Explorator for determining the changes in the size of the 

 heart of the tortoise. (Plate 8 and 8 bis.) 



9. Apparatus of " Donders " for verifying the correctness of 

 tympana. 



10. Myograph. for transmission. 





Sphygmograph for transmission placed in position on the wrist. 



11. Myograph, direct, double. 



12. Myograph, direct, single. 



13. Myograph of the heart. (For these 3 apparatus, Plate 12 

 to 12 3 .) 



14. Explorator of the movements of liquids in an elastic tube. 

 (Plate 14 and 14 bis.) (Sec opposite.) 



15. Explorator for investigating the pressure of the foot in 

 human progression. 



15A.1 



15B. > feet of the horse. 



15c.J 



16. Apparatus for showing the action of muscular elasticity. 



17. Tracing on paper transferred direct to wood. 



18. Registering cylinder, with "Foucault" regulator, and rota- 

 tory hopper, by Marey. 



