1«0j] 



New Patents lately enrolleJ. 



133 



are ufually rriade of enamel, on a plate of 

 metal, by mi'iUng or fufion : .'litfe ai e very 

 li,ible to crack, by the expanfijii an.i con- 

 tiafllonof two thiu fuhftancef, the one 

 bsin;^ of meMl, aiiu the other of a vitrious 

 fubftanre, k> ciofciy ur.ittd and unequally 

 operate i upon by heat and c IJ. 



To remedy this evil the j>iii\niee makes 

 the enamelled 'pluss wi.liout any metallic 

 fiibifance, and of a .'uilicient tliickntfs to 

 admit oF giinding and prdifiims; peifi-Ctly 

 fiuooth and fl>t, as lookinj-g'sis plates 

 are poKdud. The p'a'cs lb pjliflied are 

 ihei fixed on metil plates by means of 

 gum or cem;nt ; or by means 4.f fetting 

 ihcm by tcirning over the edge of tlie 

 met d, as in jewcdery, and thcicby fixing 

 them to'eti.er, fo as to keep them in phice 

 and conneclL'vl, hut not fo clalcly as when 

 the enamel is fluxed en the metallic plate. 



MR. C. F. MOLLERSTEN (HACICivEy), 



for a Chemical Cin:pofii:on and Method 



of applyi-!!^ the fame in the Preparation 



cf Lcaiiicr, Silks, Taffetas, and Lima. 



The compofitlon prepaicd for the black 

 colour confiits of two gallons of linfeed- 

 oil, one gallon of whale oil, and half a 

 pound of horie-grcafe mixed together with 

 four pounds of fine-ground PnUrn-blue 

 and four pounds of Ismpblack, and boiled 

 on a ftrong fire ; to this add one pound of 

 finely-ground b;nzo;ri-gum, mixed in a 

 gjlLo cf linlced-oil, of which half a gal. 

 ion is put in when the compoiition has 

 boiled h:'.!fan hour, and the re(t when it is 

 boiled lufficicnily, that is, when it is fo 

 thick that no drops fall from a-^y thing 

 dipped into it j and when cold it is fit for 

 ' ule. 



For other colours the genuine llnfeed- 

 cil niuft he well bleached ; to two gallons 

 cf which put half a gallon of I'rierniaceti- 

 oil, and hnlfa pound of Prufli'.n blue j 

 place them in a giafs vefTel in afl:nng fun, 

 and when they have attained th'i fame 

 toiififlciicy as the black connpcfitifln, after 

 having boiltd half an hour, lake a pound 

 of benziin-y.iim, mixed with a gr.ll-jn of 

 Imfeed-cil blc.ched, and add it as before. 

 1 he colours u.'ed are tiiofe comp fed of 

 metallic and animal parts, or metallic 

 only. 



The mode of woiking the leather, and 

 the ncccffary iiTiph-mcnts, are ai folio-.v ; 

 For leather, aftfr h .vIut Ijctn v,ti! cur- 

 riecf, draw it out with pincfrrs, and njil it 

 on a board to fit the i.vc.t, wh'cii l;o:ird 

 iiift rover v/ith woollen blankefs, and 

 ihen lay the compofition on the oi«!ile cf 

 the leather as thin m poSfibie, by ulliig 



McNTiiLr Mag. JSIo» 137, 



iron fcrapers of proper dimenficns. Every 

 time t'ne co-iipofition is fo laid on leather, 

 put the board into the oven to d y 'he 

 compofition ; ar,d when it is taken out of 

 the oven dry, and previous to the com))o- 

 fition being again put on, the leatlnr mull 

 be well rubbed with pumlci-llo e, to 

 fmaxh it, and make the compoliti n fafteri 

 on better. When this is done, md the 

 leather pcfTefus its regular glols all over, 

 it is to be fpeedily tak^n looie frcim the 

 bosrd, and v^hen coll it u ready for ufe. 



The number of times the com;iofitioa 

 fliouid be put on the leather is vey u-cer. 

 tain, as it depends entirely on its quality. 

 Silks, taffit.is, and linen, are done in the 

 fame manner. 



The drying of the leather is done in an 

 oven or furnace ; through two won dcors 

 in the front of the oven, r.s large as the 

 op::.ing, the boards are put in the oven on 

 i!on rails, which 2re placed on the two- 

 length fides. The fire-pfice is made to. 

 wards one fide un;'er the oven, and the 

 flames and fmoke go under and on all fides 

 round the oven by means of a fire- proof 

 flue. A. flow fire muil be kept during the 

 working of the leather, not higher than 

 fixty degrees. All boots mull be done, 

 formed, or (haped, oa blocks previ :us ti 

 their being prit in the oven. So:ne wool- 

 len-duff m-.dt be put between the wood and 

 the Ic-. I her, to prevent :hs heat fVom af- 

 fcftm.j it. 



MR. J, C. STEV2NS (mEW BOND- 



STR-iiET;, Jcr'a Mtthod of generating 

 Steam, 



By fume experiments Mr. S. found that 

 the elasticity if iteam, at tiie temperature 

 of boiling oil, or 600", was equal to up- 

 wards of fortv times the prefFure of the at- 

 mofphere. Upon the application of th;» 

 principle rief»e .ds this invention, which 

 confi(fs in (oimlng a b.ilrr by mea.-;S of a 

 combination of a number of liriall vcflels, 

 inittad of. a l.-^rge one ; the relativs 

 lirength of the niaierids of whicii thcfe 

 vefTcis are ccmno.'ed increafing in propor- 

 tion to the diminution of capacity, Mr. 

 C. gii'es the foilowirg defcriptioii of a 

 b'jiicr which he reckons the be it. 



Suppoi'e a plate of biafs, of one foot 

 fqu .re, \n which a ni!rt>ber of holts are 

 perforti'td, into each of vvliii:h is fixed ore 

 end of a copper tube, an irch in dianic'cr, 

 and two feet long, and the other cad of 

 t!ie tube ir.fvtted in like ni;in. er into a 

 fiinil.'O' piece of brafs ; the lubeS lobe calt 

 in the pUtts. Thele pla'es are to be in- 

 clol'ed ot ei'.ii end vl the pipes by a ilrong 

 U cap 



