case orby versus lord Mohun e contra April Lord keeper Lord chief justice holt  Lord chief justice Trevor Lord chief justice holt differ in opinion from the  Lord chief justice Trevor and from the Lord keeper and hold that the lease be  good and the rend certain enough it must be admit that a power to lease  reserve the ancient rend be a certain power and well enough to be understand  what it be and what it mean and why shall the same word that create and reduce  the power to a sufficient certainty when turn into a lease render it uncertain  the same certainty that be in the power be carry ever into the lease which be  the execution of it but neither in the one or the other be it mention what the  old rend be but that lie in a averment as it be hold in Whitlocks case   b and  that be certain which maybe make certain in the case of abbot of Strata  Marcelia   a reference to a former grant the same as if former letter patent  have be recite a lease reserve the rend and service ind prius debit a et de  jure consuet be a good reservation sir John Mollins case Rep fol a that shall  be deem the Vernon chancery case ancient rend which be the rend at the time  the power be reserve or when the last lease before be make if the estate be  not then under lease Hardresss report fol morris and Antrobus the word ancient  be not use in respect to the time pass but in respect of the lease to be after  make if a dean and chapter have once increase their rend they can never go  back because the statute restrain it but tenant in fee have a absolute power  to diminish so that the last rend before the creation of the power be to be  deem the ancient rend and although all be comprise in one lease it be the same  as if it have be in several knight case   b and winter case dyer b there may  be several reservation in one lease if the demise be joint yet if several  reservation they shall be take to be several Rep fol justice windham case a  lease for forty year to commence after the expiration of two former lease  which end at different time when the first lease expire it shall commence as  to that part but here in the grant part it be say several and distinct and not  joint Rep sir Edward clear case   b and the case of kibbet and lee hob what be  void as a deed or will may be a good appointment or execution of a power and  therefore in his opinion the lease as to the land ancient demise be a good  lease although not as to the Vernon chancery case er p demesne and land not  usual demise nothing be more uncertain than what be the best improve rend but  the Lord keeper and Lord chief justice Trevor be of opinion that the lease be  void as to the land not usual demise that be give up the remainderman can not  tell what rend to demand and it be in great measure in the same uncertainty as  to the land usual demise and of the rend Payable for they as the intent of the  settlement be Vernon chancery case that the tenant for life in possession may  lease so it be on the other hand that the revenue shall not be diminish but  the ancient rend at least reserve and in such beneficial manner as may with  certainty and without any difficulty be recover and for that reason it be  provide that there shall be a counterpart of the lease that it may the better  be know what the rend be and how to recover it if the rend have be mention in  the lease there if the tenant have refuse to pay it the proof will have be  turn upon the tenant to show the rend in his lease vas not the ancient rend  and if he shall do so it will make his lease void but as this lease be  contrive the remainderman may be baffle and nonsuit twenty tinniest before he  can declare or avow in certain for the rend Payable in the lease and yet the  tenant still hold the land and do not prove his own lease void as must have be  do in the other case all beneficial clause and reservation ought to be observe  in the Lord Mountjoys case if the rend be ancient reserve quarterly and now be  reserve halfyearly the lease be void if silver instead of gold if two farm  former let at pound each be both demise at pound per and not good the question  here be not whether the lease be void for incertainty as between the lessor  and lessee but whether all requisite be observe and such beneficial clause and  reservation as ought to have be for the benefit of a three person the  remainder man where there be a power of lease in general word as reserve the  ancient rend in the execution of the power which be to be explain and make  certain the rule that which is fixed be quod that which is fixed To give back  to be able be to be understand of a reference to that which be absolute  certain as to former letter patent or the like but this be rather a delegate  the power of lease to the plaintiff than a execution of the power and be the  first attempt of the kind and it be a good rule that what never have be ought  never to be and therefore adjudge the lease to be void vide ante p S c