ANNOUNCEMENT. 



THE present Volume completes this Series of Tracts on Phy- 

 sical Science, and its applications. In bringing the Work thus 

 to a close, the purpose of the Author and Publishers has been to 

 confine the collection within such a limit of bulk and price as 

 may be compatible with the leisure and the means of the great 

 majority of its Subscribers. The whole series is now comprised 

 in the moderate limits of twelve single volumes, in ornamental 

 boards, at 18s., cr six double volumes, in cloth, lettered, at 21s. 



A desire having been generally expressed that the Series 

 should have been continued, the Publishers state with pleasure 

 that they have made arrangements for the publication of 

 another popular "Work for ' general circulation by the same 

 Author, of which full particulars will be hereafter announced. 



This New Series will be commenced as soon as Dr. Lardner 

 has completed some other works which he has undertaken. 



