All peals of _doubles_ upon five bells, which go sixty changes compleat without any _single_, by making of two _extreams_ they will go 120. And also all peals of _doubles_ upon six bells, and _triples_ and _doubles_ upon six, which go 360 changes without any _single_ or _extreme_, by making of two _extreams_ they will go 720. The _extreams_ in all these compleat peals proceeding from one and the same cause, are therefore to be made after one manner, according to this general and infallible rule: Wheresoever any two of the _extream_ bells are in course to make a change, those two bells by lying still will effectually make the _extream_. So that the making of the _extream_ in _doubles_ upon five bells, necessitates the making of a _single change_ at the same time, by reason that the two _extream_ bells which should contribute to the making of the _double_ change, do lie still; so that the _single_ change is accidental, and very improperly called the _extream_. When the _extreams_ in _triples_ and _doubles_ upon six bells are made at _double_ changes, then there happens two _singles_ in the peal; but when they are made at _triple_ changes, then those two changes will become _double_, and consequently the 720 will then go compleat without any _single_. Upon five bells the first _extream_ must be made within sixty changes from the beginning, and the second _extream_ just sixty changes from the first. Upon six bells the first _extream_ must be made within 360 changes from the beginning, and the second _extream_ just 360 changes from the first. The easiest way in practice, is to make the _extremes_ at the leadings of the _whole-hunt_; wherein it may be observed as a general rule, That in all peals upon six bells, where the _half-hunt_ dodgeth behind at the _bobs_, there the first _extream_ may be made either the first, second, or third time: the _half_ and _quarter-hunts_ dodg together behind, and then the second _extream_ must be made the third time those two bells dodg again together behind, after the first _extream_ is made. And also in all such peals upon six bells, where the _doubles_ at the leadings of the _whole-hunt_ are made on the four middle bells, there the first _extream_ may be made either the first, second, or third time the _half_ and _quarter-hunts_ do make a change in the _2d_ and _3d_ places, and then the _2d_ _extream_ must be made the third time those two bells come there again to make a change after the first _extream_ is made. The _singles_ at all these _extreams_ must be made by the _half_ and _quarter-hunt_. The first _extream_ in any peal may also be made at any place, where two of the _extream_ bells are in course to made a change according to the preceding general rule; and then the making of the second _extream_ may be guided by observations taken from the changes at the leadings of the _whole-hunt_: for at the leadings of the _whole-hunt_ the _half_ and _quarter-hunts_