27 S Notices refpeEl'ing Neiv Booh. 



pound-weig'nt, than that it is as heavy as 758o grains of 

 wheat taken from the middle of the ear*. 



" Thefe ideas were naturally fuggefted to the minds of the 

 authors by the neceffity which they have been under, in the 

 courfe of their trade, of deciding on which of the various dif- 

 cordant authorities thev fliould found their eftimation of the 

 weight of given meafures of different fluids, and of the rela- 

 tion which thefe meafures of capacity bear to the linear mea- 

 fures of the country; and there cannot, perhaps, be aflronger 

 proof of the propriety of a declaratory aft to fettle thefe mat- 

 ters, than that there (hould (lill remain fomelhing to be 

 affiimed with refpeft to every one of them. This important 

 meafure is, however, as the writers of this cflTay believe, now 

 in the contemplation of the government. 



" It is ilalcd in § i6, that they have eflimated the wine- 

 gallon at 231 cubic inches, the pound avoirdupoifeat 7000 

 grains troy, and the relation between troy weight and linear 

 imcafure to be fuch, that the weight of a cubic inch of di- 

 itilled water at 60'^, when weighed in air at 60°, fhall be equal 

 to 253; of the fame grains. 



" The afriimption with regard to the wine-gallon is founde<J 

 on the eftabliflied praftice of the Boards ofCuftomsand Ex- 

 .cife to confider it as of the content which is here given ; it 

 being fufficiently known, from a very accurate experiment 

 which was made on this fubjeft May 25, 1688, in the pre- 

 fence of the Lord-Mayor, the Commiffioners of Excifc, Dr. 

 Hallev, Mr. I'lamrtead, and other men of fcience, that th? 

 pld wine gallon in Guildhall really contains only 224. The 

 former, hov;ever, is, perhaps, at the prefent day, the legal 

 wine gallon. 



*' The fuppofition with refpeft to the relation betweeri 

 avoirdupoifcand troy weight, is chiefly founded on a kind of 

 tacit agreement amongfi: the majority of fcientific men at 

 prefeat to confider the avoirdupoife pound as equal to 7000 

 grains troy ; and that which is, {jcrliaps, of ftill more prac- 

 tical efrec?t with regard to it, — the opinions of the beft in- 

 formed amopgfi: our fcalc-makers : for, whether it arifes from 

 tlic fmallcr value of the articles which are weighed by the 

 former, and its confequcnt iefs minute fubdivifion ; from its 

 introduction by cuUom rather than by ftatule ; or from what- 

 pver other caufe it may be derived, it appears to have been 



* ' P-. ,• Oidinacionem tocius rcgni Anglie fuit inenfura domini rce;is 



•Compoilt.'i, vi<!elicer, quod dennrius qui vocatur fterlinj^us rotunilus et fine 



foiilijrn pon'ki iDit tri^'inri duo gra.u frumenti in medio Ipxe. Et uncia 



poudcratjit yigiiui denaiio>. ICt duodciim uncie faciunt libram London." 



Stat. "De Pondtribus ct Menroris."3i Ed. I. 



always 



