New Patents. 317 



ALTERATIONS AND ERRATA 

 In Mr. Watcrston's " Exposition of a New Dxjnamico- Chemical Prin- 

 ciple," inserted in the Phil. Mag. and Annals for September*. 



In pao-e 175 leave out the words following the formula .'% 

 f^ ° 'HzSo (If 



beginning with " if no elastic force is supposed to he exerted. Since 

 perfect resiliency however" &c., and ending with "further to diminish 

 the rectilineal motion of the particles." 



Insert in place of the above. — It we suppose it equally probable that 

 the point of concurrence p, may be anywhere situated in the lines 

 ab, df, the extreme cases will be where it coincides with their extre- 

 mities and centres of gravity. In the former by the above formula 

 the rotatory momentum would be -^ of the whole, in the latter it is 0. 

 The mean quantity or -rV will therefore be the ratio of the whole 

 quantity of rotatory momentum generated in the medium on this 

 supposition. But amidst the diversified concourse of the particles, 

 there are peculiar modes of concurrence which do not hold with this 

 supposition and which in regard to the total effect throughout the 

 medium will tend to augment the above ratio. 



Page 170, line 23, for actual read active. 



— 174, — 31, — particulars — postulates. 



— 177, — 28, — will continually replace the, read will be 



continually renewed by the 



— 179, — 34, — theories read theorems. 



LIST OF NEW PATENTS. 



To W. Sumner, Hose, Leicestershire, lace-maker, for certain 

 improvements in machinery for making lace, commonly called 

 bobbin net. — Dated the 3rd of February, 1831. — 6 months allowed 

 to enrol specification. 



To G. G. Gardner, New York, but now residing at Thread- 

 needle-street, gentleman, for an improved roving machine. Com- 

 municated by a foreigner — 11th of February. — 6 montiis. 



To W. W. Richards, Birmingham, gun-maker, for certain im- 

 provements in the touch-holes and primers, suitable to percussion 

 guns, pistols, and all sorts of fire-arms fired upon that principle. — 

 11th of February. — 2 months. 



To J. Gunby, George-street Sand Pits, Birmingham, artist, for 

 an improved method or methods of combining glass with metal, 

 metals, or other substances, applicable to various useful and orna- 

 mental purposes. — 11th of February. — 2 months. 



To C. Guillotte, Crispin-street, Spitalfields, machine- maker, for 

 an improvement in the rack applicable to the battons of looms, or 

 machinery for weaving plain or figured ribbons. Partly communi- 

 cated by a foreigner. — 11th of February — 6 months. 



• Cnmniuiiicatcd by Mr. Watcrston. — We received this article last 

 month, but too laic to allow of its insertion in its proper plate. 



LUNAR 



