C iii 3 
ADVERTISEMENT. 
T'he Committee appointed by the Royal Society to direct the pub- 
lication of the Philosophical Transactions , take this opportunity to 
acquaint the Public, that it fully appears, as well from the council- 
books and journals of the Society, as from repeated declarations 
which have been made in several former Transactions , that the 
printing of them was always, from time to time, the single act of the 
respective Secretaries, till the Forty-seventh Volume: the Society, 
as a Body, never interesting themselves any further in their publi- 
cation, than by occasionally recommending the revival of them to 
some of their Secretaries, when, from the particular circumstances 
of their affairs, the Transactions had happened for any length of 
time to be intermitted. And this seems principally to have been 
done with a view to satisfy the Public, that their usual meetings were 
then continued, for the improvement of knowledge, and benefit of 
mankind, the great ends of their first institution by the Royal 
Charters, and which they have ever since steadily pursued. 
But the Society being of late years greatly enlarged, and their 
communications more numerous, it was thought advisable, that a 
Committee of their members should be appointed, to reconsider the 
papers read before them, and select out of them such as they should 
judge most proper for publication in the future Transactions; which 
was accordingly done upon the 26th of March, 1752. And the 
grounds of their choice are, and will continue to be, the importance 
and singularity of the subjects, or the advantageous manner of 
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