▁the ▁class room ▁session ▁in ▁which ▁a ▁teacher ▁records ▁attend ance ▁and ▁makes ▁announ c ements ▁ ▁Sign ific ant ▁weather ▁advis ory , ▁a ▁Special ▁We ather ▁Stat ement ▁advis ing ▁inc lement ▁weather ▁is ▁likely ▁or ▁im min ent ▁ ▁See ▁also ▁ ▁Ad vice ▁( disambiguation ) ▁ ▁Ad vis ory ▁Council ▁( disambiguation ) <0x0A> </s> ▁Gen aille – L uc as ▁r ul ers ▁( also ▁known ▁as ▁Gen aille ' s ▁ro ds ) ▁are ▁an ▁arithmetic ▁tool ▁invent ed ▁by ▁Henri ▁Gen aille , ▁a ▁French ▁railway ▁engineer , ▁in ▁ 1 8 9 1 . ▁ ▁The ▁device ▁is ▁a ▁variant ▁of ▁Nap ier ' s ▁b ones . ▁ ▁By ▁representing ▁the ▁carry ▁graph ically , ▁the ▁user ▁can ▁read ▁off ▁the ▁results ▁of ▁simple ▁multiplication ▁problems ▁directly , ▁with ▁no ▁intermediate ▁mental ▁calculations . ▁ ▁History ▁ ▁In ▁ 1 8 8 5 , ▁French ▁math ematic ian ▁Éd ou ard ▁Lucas ▁pos ed ▁an ▁arithmetic ▁problem ▁during ▁a ▁session ▁of ▁the ▁Ac adémie ▁française . ▁Gen aille , ▁already ▁known ▁for ▁having ▁invent ed ▁a ▁number ▁of ▁arithmetic ▁tools , ▁created ▁his ▁r ul ers ▁in ▁the ▁course ▁of ▁solving ▁the ▁problem . ▁ ▁He ▁presented ▁his ▁in vention ▁to ▁the ▁Ac adémie ▁française ▁in ▁ 1 8 9 1 . ▁ ▁The ▁popular ity ▁of ▁Gen aille ' s ▁ro ds ▁was ▁w ides p read ▁but ▁short - l ived , ▁as ▁mechanical ▁calcul ators ▁soon ▁began ▁to ▁dis place