OF CHURNING BUtfTER. 241 



the fri&ion of the axis, &c. it will at all times defcend (lowly 

 within the refervoir, and raife the boat, when left at liberty 

 fo to do ; and if inftead of being allowed to defcend the whole 

 eight feet required, it be ftopt after having defcended feven 

 feet, the admiffion of one foot depth of water from the upper 

 line into the lock; may be fufficient to raife the plunger again 

 with the lofs of only Jth part of a lock-fall of water. 



Plate XII. Fig. 1. Exhibits a perfpe&ive view of a model View of the 

 of the apparatus above defcribed, having part of the front a PP aratus « 

 taken away in order to fliew the interior parts. 



A. Reprefents the upper fluice of the lock. 



B. The lower fluice. 



C. The plunger. 



D. The fnail upon which the weight or chain is wound that 

 carries the counterpoife. 



VIII. 



An eajy Method of Churning Butter. By Cit. Jumijlhac, 

 Prefident of the Society of Agriculture, of the Seine and the 

 Oife*. 



JL O increafe the powers of man, is one of the attributes of 

 mechanics, but in order that a mechanical contrivance may be 

 truly ufeful, it is requifite that it it mould be fimple and cheap. 

 That which I now offer to the fociety, appears to me to unite 

 thefe two advantages. 



It is univerfally known, that in great heats and extremely 

 cold weather it is difficult to churn butter. The labour of 

 feveral perfons fucceflively, is often applied without any 

 fuccefs, to procure the perfect coagulation of the cream. 

 In vain during the rigour of winter, the cream is placed by 

 the fire, or mixed with milk quite frefh and yet warm ; and it 

 is with as little fuccefs, that in fummer the churn ftaffis occa- 

 fionally immerfed in cold water. All thefe means though of 

 value, are infufficient if not feconded by celerity of motion in 

 the act of churning. 



Surprifed at the flownefs with which butter is formed, efpe- 

 cially in winter, and after having continued the operation for 



* Sonin'fs Bibliotheque Phyf. Oeconomique, No. 1, 

 Vol. IV.—Apkil. R five 



