Images Dated 18th February 2003

Historical celestial system

Historical celestial system. Illustration of the celestial system proposed by Athanasius Kircher in his 1660 work Iter extaticum coeleste. At top is a map of the spheres surrounding the Earth (centre), including the air, fire and the stars. At bottom is a model of the Earth (centre) with the equator, the tropics of Cancer and Capricorn, the horizon, the poles and the ecliptic (the line along which the Sun, Moon and planets appear to move) mapped onto the sky

© SCIENCE, INDUSTRY & BUSINESS LIBRARY/NEW YORK PUBLIC LIBRARY/SCIENCE PHOTO LIBRARY

Static electricity experiments

Static electricity experiments, historical artwork. Turning the wheel at lower right creates a charge on the man on the trapeze, which he passes to the girl on the wooden (non-conducting) block. She is observing the effects on a pile of small flakes. This illustration is from Recueil de Traites sur l'Electricite, Traduits de l'Allemand & de l'Anglois, seconde partie, published in 1748

© SCIENCE, INDUSTRY & BUSINESS LIBRARY/NEW YORK PUBLIC LIBRARY/SCIENCE PHOTO LIBRARY

Salivary gland

Salivary gland. Coloured scanning electron micrograph (SEM) of a transverse freeze-fractured section through an acinus (large brown circle) in a salivary gland. The rest of the image comprises several other acini surrounding this acinus. Acini are the smallest unit of a gland. They comprise a circular cluster of cells that secrete fluid into a central duct (hole, centre) that leads to larger ducts. These acini are secreting granules (lumps, brown) of mucus, the natural lubricating fluid found in saliva. Each acini is circled by a layer of connective tissue (pink). Saliva is secreted into the mouth to aid digestion and the process of swallowing. Magnification: x1000 at 6x7cm size

© Steve Gschmeissner/Science Photo Library