36 Josiah Wedgwood CHAP. 



spacious, and the soil so good as to promise ample 

 recompense to any one who should labour diligently in 

 its cultivation. 



" In the following experiments I have expressed the 

 materials by numbers, which in this instance are a 

 species of shorthand, and saved much writing. They 

 have also the advantage of not being intelligible, with- 

 out the key, to any person who might happen to take 

 up the book, which is often, in the course of making 

 the experiments, unavoidably exposed to such an acci- 

 dent." 



Then follows the key to the cipher, giving the 

 numbers and letters employed in noting the experi- 

 ments. These represent the nature and quantity of the 

 materials, the degrees of heat to which they had been 

 exposed, together with miscellaneous observations, con- 

 clusions, and hints for further inquiry. 



"The degrees of heat," says Wedgwood, "in my 

 former books, were expressed by the different ovens, and 

 the different parts of them where the experiment pieces 

 had been fired in. G. 0. signifies the gloss oven ; B. 0. 

 the biscuit oven ; W. 0. the white oven ; and the letters 

 B. M. T. prefixed to these mean the bottom, middle, and 

 top of the respective ovens. T. B. 0. means the highest 

 part of the biscuit oven in which we put ware. It is 

 below the top of the chimneys or flues, called lags by 

 the potters ; and T. T. B. 0. signifies the uppermost 

 sagger of the pile, except the one with which it is 

 covered. 



