INTRODUCTION, 



THIS Society having, in its Book of 

 Premiums for 1787, announced an 

 intention of fbon publifhing a Fourth Vo- 

 lume of Papers; the public had certainly a 

 right to expeft an earlier fulfilment of that 

 intention. 



For the delay, feveral reafons might be 

 afligned; among which, and not the leaft 

 operative, was the deceafe of Mr. Edmund 

 Rack, the late ufeful and ingenious. Secre- 

 tary of this Society. By that event was dif- 

 folved an ideal arrangement of materials $ 

 and even for fome time was fufpended, a 

 certainty to whom fome few of the MSS. 

 had been lent for perufal. 



On adverting, afterwards, to the promife 

 of publication, fome of the moft a£tive 

 Members of the Society, though agreeing 



Vol. IV. b on 



