388 Decisions on Disputed Inventions and Discoveries. 



the elongation of the rod. One of these pendulums is in use at the Albyn 

 Club ; but, though ingenious contrivances, we have not learned that they 

 are superior to those invented by Elliott, Wood, Reid, and Troughton. 



The pendulum now under our consideration, is not the invention of Mr 

 Bryson, but was invented by Mr David Ritchie of Clerkenwell, who re- 

 ceived for it the medal of the Society of Arts, and who has published 

 a full account of it, with drawings, in the Transactions of that body, 

 vol. xxx. p. 176 — 182. 



3. Sir William Congreve's Moveable Ball Clock, invented by M. Serviere- 

 The Cognoscenti in elegant mechanism have long been in the habit of ad- 

 miring a beautiful time-piece, which bears Sir W. Congreve's name, (but 

 whether with or without his sanction we know not), in which the minutes 

 are indicated by the descent of a brass ball, along a number of inclined 

 planes running alternately from right to left, and left to right, on the face 

 of an inclined brass plate. When the ball reaches the bottom of the plate, 

 after having described the last of the inclined planes, it releases a detent 

 which tilts the brass plate, and inclines it in the opposite direction. The 

 ball being now at the top of the system of inclined planes commences its 

 retrograde motion, and when it again reaches the. bottom, the plate is again 

 tilted at the opposite position. 



This clock was invented by M. Serviere, and is minutely described in 

 various forms in a French work, which we have now before us, entitled 

 Recueil d'Ouvrages Curieux, &c. Lyons, 1719. In all these clocks, however, 

 the ball is carried up by machinery from the bottom to the top of the in- 

 clined plane, whereas, in Sir W. Congreve's, the plane is moveable, as 

 above described, which is a very important improvement. 



4. Heulandite first separated from Stilbite by Professor Mohs, and not by 



Mr Brooke. 



In the Ed. Phil. Journal, January 1822, Mr Brooke has given an ac- 

 count of his determination of the radiated and foliated zeolite of Werner 

 to be two distinct species, and he has given to the latter the name of 

 Heulandite. 



The merit, however, of first separating these two species, belongs to 

 Professor Mohs, who published the results under the titles of Prisma- 

 toidal and Hemiprismatic Kouphone Spar, in his Characteristic, p. 59, 

 which was translated and published in Edinburgh in the year 1820. 



In Mr Brooke's Familiar Introduction to Crystallography, published 

 in 1823, he has not taken the opportunity of mentioning the prior claims 

 of Professor Mohs. Mr Phillips has also overlooked this, but we expect 

 to see it in the next edition of his Mineralogy. 



5. Mr Nicholas Mill's Plalina Pyrometer. 

 We have much pleasure in laying before our readers the following can- 

 did and liberal explanation sent to us by Mr Mill, regarding the similarity 

 which we pointed out in our last number between the Platina Hygrometer 

 proposed by Dr Ure, and the Platina Hygrometer executed by himself. 



