EXPERIMENTAL DRAWING-FRAMES. 147 



did not afford him space enough for a sketch of suffi- 

 cient magnitude ; while, even with drawings of lesser 

 size, the available space became so rapidly filled that 

 the constant use of the sponge and towel was necessary. 

 And, thirdly, he wanted a more yielding, more elastic 

 surface. He had now taken to drawing with pastils of 

 many colours some manufactured specially for himself 

 instead of with the plain white chalks as at first. The 

 hoard did not " take " these colours well ; and the 

 pastils, moreover, were for the most part so soft that 

 the pressure against the unyielding wood crumbled 

 them into fragments, so that they could not be used 

 with any degree of certainty. So the big blackboard 

 was doomed. 



But what was to be substituted for it? Mr. 

 Waterhouse Hawkins, who about this time had been 

 lecturing at the Crystal Palace, had employed a large 

 sheet of black canvas, loosely stretched by means of 

 guy-ropes ; but this did not at all fall in with my 

 father's fastidious requirements, and certainly was 

 rather too much of the " rough-and-ready " descrip- 

 tion for use upon a public platform. So he devoted 

 himself heart and soul to the designing of a more 

 worthy substitute. 



One or two failures, of course, were inevitable. He 

 soon saw that the canvas must be stretched on a wooden 

 frame, but fell into the error of making this frame too 

 light; so that when the strain of the canvas was thrown 

 upon it, it collapsed, and proved utterly unsuitable to its 

 purpose. After quite a long succession of experiments, 

 K 2 



