SUPPLEMENT. 



Engravings of the following Objects : i. Improvement in the Striking 

 Part of Clocks, by Mr. Ward. — 2. A Machine for cutting the 

 Edges of Books, by Mr. Hawkins. — 3. Machine for the transfer of 

 Boats through the Locks of Canals with the least possible consump- 

 tion of Water. 



I. Observations and Experiments to shew that the Effects ascribed 

 by Mr. Dispan to the perpendicular Descent of Hoar Frost are not 

 so general as to support his Theory. In a Letter from J. Gough, 

 Esq 341 



II. Description of an Eight-day Clock, with an improved Striking 

 Part, by Mr. Henry Ward, of Blandford, Dorsetshire 346 



III. Description of a Model for elevating and depressing Water, 

 applicable to the use of Canal Locks, and for preventing the usual 

 waste of Water therein, with Directions for working the same. 

 By Mr. R. Salmon 348 



IV. Observations, chiefly mineralogical, on the Shetland Islands, made 

 in the course of a Tour through those Islands in 1803. By Dr. 

 Traill 353 



V. Facts toward forming a History of Silver. By Professor Proust 367 



VI. Description of a Machine for cutting Paper and the Edges 

 of Books. By Mr. J. J. Hawkins 381 



VII. Observations on the Permanency of the Variation of the Com* 

 pass at Jamaica. In a Letter from Mr. J. Robertson to the Right 

 Hon. Sir J. Banks, K. B. P.R.S. &c 38^3 



VIII. Observations and Remarks on the Figure, the Climate, and the 

 Atmosphere of Saturn, and its Ring. By Wm. Herschell, LL. D. 

 F.R.S 390 



IX. Scientific News: Report of the Transactions of the Class of 

 Mathematical and Physical Sciences of the National Institute of 

 France for the preceding Year 400, 



