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PREFACE, 
these researches ; and by the insertion, in almost every 
sheet, of treatises or disquisitions composed expressly 
for the purpose, the whole composition of a Dictionary 
of Science shall bear the marks of originality, it becomes 
a duty in the Editor, with regard to himself and the 
other writers, that he should, to a certain extent, point 
out what has been done in this respect. 
It would be truly gratifying to the Editor if he might 
attempt in this place to express his sentiments of the 
treatises which have passed under his view in the con- 
duct and disposition of the present work, and declare 
his obligations individually to each of the writers who 
have honoured him with their assistance in the comple- 
tion of the undertaking ; but he fears that the language 
of approbation which he would in justice feel himself 
compelled to use, might be misconstrued into an un- 
becoming endeavour to enhance, beyond its merits, the 
value of the publication. Some of the authors of the 
British Encyclopedia have chosen to reserve their names. 
The Editor has written and composed upwards of two 
hundred articles on Chemistry, Natural Philosophy, and 
Mechanics, and practical subjects relating to them, be- 
sides several of the lives of great men. The Mathemati- 
cal Articles, including the mixed subjects of Astronomy, 
Optics, Phonics, Statics, and many others, were drawn 
up by a popular author who is well known for his 
writings on those subjects. The article Conic Sections 
was written by James Ivory, Esq, of the Royal Military 
College of Marlow, To the Rev. Dr. Carpenter, of 
