To the Reader
That the reader may form feme idea of what has been done for his ferv!cc, and of the manner in which this performance hath been conducted, he will be pleafed to obferve ;
i. That the plan, of the Cyclopaedia has been, in general, adhered to, with this improve-' fnent upon it; that proper authorities are almoft every where quoted, in the double view of producing vouchers for what is advanced, and of directing fuch as want further information where to find it.
2. That care has been taken to connect the Supplement with the Cyclopaedia, fo as to make the whole in a manner but one work ; it being always referred to for thofe articles which, having been treated of there, are here re-confidered, and enlarged, or corrected ; every fuch article having the fyllable Cycl. annexed to it, as a direction to confult the Cyclopaedia firft on that head.
3. That the main end of the work being kept always in view, fome branches of learning have been treated much more at length than others, with a due preference to the moft interefting : Nor is it to be feared that the reader will condemn a diftinction fo much to his own advantage.
On this principle it was judged improper to fwell the book with details of the fubtilties of fchoolmen, and the frivolous and vague queftions debated among them. Nor did the niceties of philology and lite- rature feem to deferve much more notice than has already been taken of them in the Cyclopaedia. In general, the additions on all thefe heads confift chiefly of the explanation of fome terms omitted in that work. However, many fubjects of this kind are more fully treated here, with additional illufrra- tions of thofe of alike nature found in the Cyclopaedia.
On the other hand, natural hiftory, and the other branches of real knowlege, have been chiefly at- tended to ; moil of the various articles relating to thefe fubjects, which are to be found in the Cyclopae- dia, being here very confiderably enlarged, and a multitude of new ones fuperadded.
Tho' great regard ought to be paid to the mathematical and phyfico-mathematical fciences, on ac- count of their find connection with the knowledge of nature, yet as it was not proper, nor indeed practicable in a work of this kind, to give more than general and hiftorical views of them, and as the Cyclopaedia already contains extracts from the beft elementary writers on thofe fubjects, large additions were judged unneceflary. However, feveral new articles, both curious and ufeful, will be found in this Supplement, and in the Appendix. In particular, fuch care hath been taken to explain the principles of the modern geometry, and the methods of computation ufed in it, as to enable a reader, without any great fkill in mathematics, to fatisfy his mind that thofe things are not involved in unexplicable myftery, as the late ingenious author of the Analyft pretends ; miftaking the great inventor's concifenefs for obfeurity, and the inadequate and confufed notions of fome of his fol- lowers, for the accurate doctrines of their mailer.
With regard to manual arts and manufactures, whether depending on chemiftry or mechanics, fo eminently and extenfively beneficial to mankind, it were to be wifhed, that more complete information, than is to be found here, or in any books extant, could be given the reader. It is indeed to be lamented that there are fo very few good writers on thofe important fubjects ; but it is no wonder that thofe who underftand and pradtife them belt, fhould have the leaft leifure or inclination to communicate them to others. Above half a century paft, an illuftrious foreign academy formed the noble defign of compofing a Hiftory of Arts ; but little or nothing has as yet appeared in confequence thereof, and their ingenious fecretary juftly reprefents the difficulty of the undertaking in fo ftrong a light, that what he has faid may well ferve as an apology for the Cyclopaedia, and Supplement, if they ihould be cenfured as defective on this head. However, the reader will find feveral curious particulars relating to the arts de- pending on chemiftry.
In general it is hoped that, as the bulk of the book fhews the additions and emendations to be very confiderable in quantity, the reader will find them no lefs fo in point of pleafure and utility ; and that the purchafers of the Cyclopaedia will be fatisfied with the juflice which the proprietors have done them by printing the Supplement feparately, in the two volumes now offered to the public.
DIRECTIONS to the BINDER.
Place all the CUTS in die Order they are number'd at the End of the Second Volume,
