59 



warming. Betwccn thèse two Hues we see a dotted line 

 representing the presentation-tiine after 2 hours' and an 

 intcrrupted one representing thc same after 4 hours' 

 preliniinary warm ing. 



The same figures are represented in Fig. 7 in a slightly 

 différent way, according to Blackman's diagrams. Hère 

 thc values after différent times of preliniinary warming 

 are put down in the diagram in such a way thatateach 

 température the values at that one température can be 

 connected by means of a curve. Therefore the abscissae- 

 axis is not only used as temperature-axis, but also as 

 time-axis, so that at each definite température the hours' 

 of preliniinary warming are set down on the abscissae- 

 axis beginning with the ordinate of the température 

 concerned as starting-point. In other words the plane of 

 the drawing is the plane containing the presentation-time 

 axis and the temperature-axis. At each température between 

 80° C. and 40° C. another plane is needed containing the 

 presentation-time axis and the axis of the preliniinary 

 warming-time. Thèse last mentioned planes should bc 

 perpendicular to the first mentioned one and parallel to 

 each other. Now, for convenience sake, thèse planes are 

 turned down so as to bc in the same plane as that of 

 the drawing. In this way it bas been possible to add to 

 the diagram the curves An — Ae, Bo — Be etc., which represent 

 the relation between presentation-time and tinie of preli- 

 niinary warming at a definite température. It i^ only 

 between 38° C. and 40° C. that some of thèse points lie 

 Dutside the diagram. The scale, chosen for the time of 

 preliniinary warming détermines whether or not the curves 

 are very steep. Hère the distance between two vertical 

 lines has been made equal to 2 hours in order to get a 

 diagram as comparable as possible to that of Blackman. 



The conclusions, which may be drawn froni the diagrams, 



