▁help ▁offset ▁the ▁mill s ▁contribution ▁to ▁global ▁war ming ▁on ▁the ▁basis ▁of ▁' Th ink ▁Global , ▁Act ▁Local '. ▁ ▁The ▁mill ▁building ▁has ▁an ▁unusual ▁struct ural ▁feature , ▁an ▁alc ove , ▁designed ▁to ▁attract ▁nest ing ▁ow ls ▁which ▁would ▁then ▁feed ▁off ▁and ▁help ▁to ▁control ▁the ▁verm in ▁which ▁stores ▁of ▁c ere als ▁and ▁other ▁food st uff s ▁always ▁attract . ▁ ▁One ▁feature ▁of ▁the ▁mill ▁is ▁the ▁relatively ▁small ▁number ▁of ▁windows . ▁This ▁may ▁be ▁purely ▁practical , ▁however ▁avoid ance ▁of ▁pay ing ▁too ▁high ▁a ▁' window ▁tax ' ▁may ▁have ▁been ▁a ▁consideration . ▁Window ▁tax ▁was ▁first ▁lev ied ▁in ▁England ▁in ▁ 1 6 9 6 ▁to ▁offset ▁the ▁exp enses ▁of ▁making ▁up ▁the ▁gold ▁and ▁silver ▁def ic iency ▁in ▁the ▁re - co in age ▁of ▁William ▁III ▁reign ▁caused ▁by ▁cli pping ▁and ▁fil ing ▁of ▁co ins . ▁It ▁was ▁set ▁at ▁two ▁sh ill ings ▁for ▁small ▁ten ements , ▁six ▁sh ill ings ▁for ▁buildings ▁with ▁up ▁to ▁ten ▁windows ▁and ▁ten ▁sh ill ings ▁for ▁those ▁with ▁twenty ▁windows . ▁C ott ages ▁were ▁ex empt . ▁It ▁was ▁based ▁on ▁the ▁number ▁of ▁windows ▁in ▁a ▁house ▁and ▁large ▁m ans ions ▁often ▁had ▁many ▁existing ▁windows ▁blocked ▁up , ▁such ▁as ▁a ▁whole ▁side ▁of ▁L oud oun ▁Castle , ▁in ▁A yr shire , ▁Scotland . ▁It ▁was ▁repe aled ▁in ▁ 1 8