146 Royal Academy of Sciences and Belles Lettres of Brussels. 



An Account of the Hydraulic Press of Count Real. By M. Van 

 Mons. — On the Mocanere, Fisnea Mocanera. By M. Bory de 

 St. Vincenl. — Description of Eight new Insects. By M. Dra- 

 piez, &c. We shall take an early opportunity of enriching our 

 pages with some of the valuable information which they contain. 



Works in course of publication by R. Ackermann : 



1 . An Historical and Characteristic Tour of the Rhine, from 

 Mayence to Coblentz and Cologne, in six monthly parts : con- 

 taining a complete history and picturesque description of a por- 

 tion of country full of curious and interesting circumstances, as 

 well as resplendent for its landscape, grandeur and beauty. The 

 work will be embellished with twenty-four highly finished and co- 

 loured Engravings from drawings expressly made by an eminent 

 artist resident near the banks of the Rhine, and habitually fa- 

 miliar with every part of it. A correct Map of the river, and the 

 territory, according to its last arrangements, through which it 

 flows, is preparing exclusively for this publication. 



2. Letters from Bnevos Ayres and Chili; with an original 

 History of the latter Country: illustrated with Engravings, by the 

 Author of " Letters from Paraguay." 



3. An Elementary ^^7-^, of peculiar interest, on the Construc- 

 tion of the Machines adopted in the Arts andManufactures; from 

 the French of M. Bdfancourt. — It will afford an analytical and 

 perspicuous display of the various combinations which occur in 

 the arrangements of the practical mechanist, with their several 

 applications to use, and constant reference to the engines and 

 machinery of this and other countries. It will be illustrated with 

 thirteen Plates of much novelty and elegance, and be altogether 

 calculated to engage the young student, and gratify the more 

 learned and practical. 



XXVII. Proceedings of Learned Societies. 



ROYAL ACADEMY OF SCIENCES AND BEIXES LETTRES OF 

 BRUSSELS. 



A HE Academy have proposed for competition during the year 

 1820, the five following questions in the department of science : 



First Question. — Suppose a plate of a given figure attached to 

 a surface either by means of screws of a known number, position 

 and force, or by means of some intermediate matter, capable of 

 uniting the one to the other solidly, and the specific tenacity of 

 which is also known ; if to a point of the circumference of this 

 plate an arm be affixed which acts in the same plane with the 



surface. 



