IV 



Partnership with Harrison & Whieldon 37 



" No other means than the above were at that time 

 known, not only of communicating to any other person, 

 but of preserving to myself, any idea of that very 

 essential circumstance in experiments of this kind, the 

 degree of heat to which the materials were exposed. 

 But having lately invented a thermometer for measuring 

 the higher degrees of heat, as far as we can go above 

 ignition, the heats made use of in the several experi- 

 ments are now expressed in the degrees of that ther- 

 mometer." 



The first record of experiments bears the date of 

 15th February 1759, and continues for several years. 

 They are systematically and minutely set down in the 

 beautiful handwriting of Mr. Chisholm, and would 

 doubtless be of great interest to any scientific potter. 

 Sometimes observations are introduced at the sides of 

 the record, such as : " This merits further trial ; Try 

 it again " ; " Coloured clays often proved in knife 

 handles " ; " Colours to paint agate on the outside of 

 the glaze after it is laid on the ware and before it is 

 fired " ; " The crucible broke, try it again." 



Under the date of 13th February 1759, at Fenton, 

 Wedgwood writes : " Trial for a blue to lay upon the 

 biscuit ware along with other colours to imitate agate 

 and tortoise-shell." Again, on the 23rd March 1759, 

 while trying for glazes, he writes : " This is the com- 

 position of Bow China, but I am not certain of the 

 proportions." Also : " This is the result of many experi- 

 ments which I have made in order to introduce a new 



