210 



RECORDING. 



This pillar can be turned by means of an arm O, which moves 

 "against a ridge with a stop at its end above M. When setting writing 

 points always bring the arm up to this stop. The points can then by 

 moving O be removed from the writing surface, and can be returned 

 to it without losing their setting. 



The pillar carries a bracket P for the attachment of muscle chamber 

 or frog-heart recorder, for which purpose the latter carry clamping 

 screws. An extension piece is sometimes useful, which fixes to the 

 bracket and the above for more convenient adjustment of points when 

 very short writing arms are employed. 



The side bar Q, a rod bent D shape is also carried by the pillar 

 lor use with time marker, &c. (See Figs. 34, 40.) 



Fixing 1 Tracing's. The soot is fixed to the paper by means of 

 resin (15P- C -) dissolved in methylated spirit. 



Free the paper from the cylinder, so as not to touch the smoked side, as 

 follows : Remove the cylinder from its axle, hold it with the left hand 



horizontally and rest the clamping- 

 boss upon the edge of the table, 

 place the thumb of the left hand 

 on the overlap of the paper, and 

 pass the point of a sharp knife 

 under it along the line of junction, 

 keeping the cutting edge turned 

 away from the cylinder. 



The detached end of the paper- 

 should fall clear of cylinder and 

 table, still held by the left thumb. 

 Raise the cylinder and paper over 

 the table and lay the paper down, 

 smoked surface uppermost. 



Next fill in such written details 

 as may be desirable concerning the 

 manner of carrying out the experi- 

 ment, date, name, &c. , writing with a 

 smooth point through the blacking. 

 Take your tracing to the var- 

 nishing table, place a pool of varnish 

 one inch deep in the trough. Hold 

 the paper by both ends, smoked 



FIG. 39. Varnishing table. P paper. surface uppermost, bring the hands 

 V varnish. F frame. B hanging rods. together so as to form the paper 



