1^8 farmers' and mechanics' journal. 



a much thinner and lighter slip of wood, and grinding the needle 

 to give it an edge. It would also be easy to make it carry small 

 scales of paper for particular purposes." 



Mr. Smithson observes, that the rings, or small weights, men- 

 tioned al)ove, have the defect of their weight being entirely acci- 

 dental, and consequently most times \ ery inconvenient fractions of 

 grains, and recommends instead that the weight of a certain length 

 of wire be ascertained, and then the length of it taken, which cor- 

 responds to the weight wanted ; when fine wire is used, a set of 

 small weights may thus be made with great accuracy and ease. 

 This is a process, the value of which is well known to the philo- 

 sophical instrument maker. [^Joiir. of Science and Arts. 



On rendering Fish Oil and Linseed Oil driving ; and on making 

 cheap Oil Paints. By Mr. T. Vanherman. 



Having applied a great portion of my time, for several years 

 past, to discover a method of preparing a cheap and durable com- 

 position for the defence and preservation of all work exposed to 

 the inclemency of the weather, 1 have now the satisfaction of lay- 

 ing before the Societ}^ for the Encouragement of Arts, &c., speci- 

 mens of some of the colors ready prepared for use, which will, I 

 flatter myself, be found superior to all others for cheapness and 

 durability, equal to any in beauty, and not be subject to blister or 

 peel oir from the heat of the sun. 



The vehicle made use of for the said paints, is fish-oil, the pre- 

 paration of which is so simple, that, when known, gentlemen who 

 have large concerns to paint, may have this composition of any 

 color manufactured, and laid on by their laborers. 



1 have sent a bottle of the prepared oil, also a number of pat- 

 terns of paints, of various colors. The highest price of any does 

 not exceed three-penoe per pound, and many of them are so low 

 as two-pence, in a state fit for use. I have likewise sent a pot of 

 white-lead, which has been ground with prepared fish-oil ; and 

 which, when thinned with linseed-oil, surpasses any white hitherto 

 made use of for resisting all weathers, and retaining its whiteness. 

 I hope my humble endeavors will merit the approbation of the So- 

 ciety, before whom I will, at any time they shall please to appoint, 

 make the various experiments they may require. 



Relying on your encouragement, I am. Gentlemen, with due re- 

 spect, your most obedient humble servant, 



Thomas Vanherman. 



To rvfine one Tun of Cod, Whale, or Seal Oil, for Painting, Ihcfol- 

 lotcing ingredients are used. 



One ton offish-oil, or 95">i galls. 

 32 frails, of viiie<;ar, 

 12 lbs. of lithar-e* 



12 Ihs. white oopperas,f 

 12 galls, of liiispcd-oil, 

 2 galls, of spirit of turpentine. 



The vitreous o.\i(lc of lead. f Sulphatg of zinc. 



