MM 



£i)6 SWITEtHEADED CHURN8TAFF. 



Certificates, Certificates from the following gentlemen testified, that 



they had experienced the efficacy of Mr. Mason's trocar, 

 had proved the safety of the operation, and the instanta- 

 neous relief which it had never failed to produce without 

 leaving any blemish, or dangerous consequence, from its 

 Application, 



John Ford Naish, Leek Wooton. 



Thomas Bryan, Warwick. 



William Oram, Warwick. 

 1 UVilliam Ledbrooke, Northend. 



Richard Cattell, Milverton. 



Reference to the Engraving of Mr. Wallis Mason's 

 Trocar and Canuia. 

 Instrument de- Fig. 1, PI. VIII, is a representation of Mr. Wallis Ma- 

 son's trocar and canuia. The blade of the trocar is of steel 

 a a, fig. 4, fixed into the wooden handle b b. The shape of 

 the blade of the trocar is oval, as shown in the end view of 

 the canuia, fig. 3. The canuia or sheath e e, figs. 1 and 2, 

 is an oval tube, which exactly fits the blade of the trocar; 

 ff is a concave circular plate, fixed at the end of the 

 canuia, forming a hilt, to prevent the instrument from 

 giving too deep a wound when used; the end g of the ca- 

 nuia is worked down to a sharp edge, that it may not ob- 

 struct the passage of the instrument. The drawings are on 

 a scale of one inch to two inches and a half; in figs. 1 and 

 2, the trocar and canuia are shown edgeways, or in the 

 shortest diameter of the ellipsis; in fig. 4, the trocar is 

 shown flat, in its longest diameter. 



VIII. 



Description of a Swivel-headed Chum Staff, to facilitate 

 the making of butter: by Mr. Timothy Fisher, of 

 Ormskirk, Lancashire*, 



SIR, 



Swifdheadei -i ^eg )eave to lay before the Society of Arts &c. my 

 »lwnstaff. swivel-headed churn staff, which, on repeated trials, is now 



• Trans, of the Soc of Arts, vol. XXVI, p. 131, Five guineas 

 were voted to Mr, Fisher for th» iuve»ti*»n, 



fully 



