Yi PREFACE. 



complete set of which amounts to nearly 100 volumes. Indeed the early 

 volumes^ indispensable to those who wish to trace the progress of science, are 

 only to be casually procured. 



To supply this want of the Original, an Abridgment was long since under- 

 taken by Mr. Lowthorp, and after his decease it was brought down by vari- 

 ous continuators to the middle of the last century. But in that Abridgment, 

 made at different times by different persons, not only was the order of the 

 Original^ in the printing of the Memoirs, departed from, but a great num- 

 ber of papers not reprinted in other works were omitted. However, not- 

 withstanding these objections, even that Abridgment is now scarcely to be 

 procured. 



Either, therefore, an entire re-impression, or a new Abridgment of the 

 Philosophical Transactions, was called for. But the expences attending an 

 entire re-impression of a work so voluminous, and containing such numerous 

 plates, must deter every individual or association from attempting such an 

 undertaking, as from the necessarily limited number of purchasers not even 

 an indemnity, much less any emolument, could be obtained. Besides, many 

 of the papers in the earlier volumes are not sufficiently important for re- 

 publication. Instead, therefore, of a re-impression of the Philosophical 

 Transactions at large, the present New Abridgment in Eighteen Volumes 

 is offered to the public. It comprises whatever is most valuable in the Origi- 

 nal, from its commencement to the close of the eighteenth century, together 

 with Dr. Hooke's volume of Philosophical Collections. All the articles are 

 presented in the same order in which they appear in the Original. The most 

 important communications are reprinted entire, in the words of the respec- 

 tive authors. The less important papers are given in an abridged state, so 

 however as to retain, it is hoped, whatever is especially curious or useful in 

 them. Those papers which, in the Original, are printed in foreign languages, 

 are here translated ; one or two instances excepted, where, from the pecu- 

 liarly delicate nature of the subject, there would have been a manifest impro- 



