The Quarterly Journal of Science and the Arts, Volume 5

acid angle appears arts ascertained Author becomes blue bodies called cause circle colours common considerable considered consists containing continued covered crystals described direction distance earth effect equal exhibited existence experiments feet figure flame flax four give given glass green heat height horizontal important improvement inches increase iron Italy known land lead length less light machine manner means measure metal minutes nature nearly necessary needle object observed obtained original passing persons plates position present principles produced proportion quantity rays reflected remains remarks respecting result river rock round Royal sciences screw seen side similar Society solution stone sufficient supposed surface taken telescope temperature tion tube turn various whole wire