animal communication - early works to 1800]]> refraction, astronomical
astronomical instruments - early works to 1800
sun -early works to 1800]]> scientific recreations - early works to 1800
practical jokes - early works to 1800]]> Galilei, Galileo, 1564-1642. Dialogo dei massimi sisterni
astronomy - early works to 1800
magnetism, terrestrial - early works to 1800
earth - rotation - early works to 1800]]> southern sky (astronomy) - early works to 1800
planets - orbits - early works to 1800
telecscope - early works to 1800]]>