[ vii ] 
ADVERTISEMENT. 
The Committee appointed by the Royal Society to direct the publication 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 publication 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 winch 
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 treating them : without pretending to answer for the 
certainty of the facts, or propriety of the reasonings contained in the several papers 
so published, which must still rest on the credit or judgment of their respective 
authors. 
It is likewise necessary on this occasion to remark, that it is an established rule of 
the Society, to which they will always adhere, never to give their opinion, as a Body, 
