312 LABOR A TOR Y G UIDE IN PHYSIO LOG Y. 



1.5 cm. in diameter) the upper edges of .the triangle 

 may be beveled and each corner may be furnished with a 

 leg by screwing into each corner from the lower surface, 

 a round headed screw, leaving about 1 cm. of the screw 

 out to serve as the leg. If the class is large, the demon- 

 strators should prepare these tambour boards in advance. 

 The tambour is mounted by fitting a cork to the hole 

 in the tambour board, boring the cork and pressing the 

 tambour tube through the 

 hole from below upward. Fix 

 a button of cork to the mem 

 brane with sealing wax. The 



completed cardiograph will 



, FIG. 5b. 



present in section the rela- 

 tions shown in Fig. 56. As will be seen from the cut, 

 the position of the button may be varied by varying its 

 shape or by changing the adjustment of the tambour tube 

 in the cork. The cardiograph tambour is the receiving 

 tambour. 



9. Tambours. 



It is probable that no part of the laboratory equipment 

 is more in use than the various forms and adjustments of 

 the tambour. The possibilities of this device were first 

 brought out and developed by Marey, Director of the 

 Physiological Institute of the 6cole des Hautes Etudes 

 en Sorboune, Paris. 



If the laboratory cannot afford to furnish at least one 

 pair of the Marey tambours to each table, recourse may 

 be had to such a device as that just described above under 

 the cardiograph. Such simple tambours when carefully 

 constructed prove most satisfactory. 



To construct a recording tambour : Use a No. 2 tambour 

 pan, stretch the rubber less tightly than for the receiving 



