An ancient astronomical instrument. Note: When composed of one ring placed in the plane of the equator for determining the time of the equinoxes, it is called an equinoctial armil; when of two or more rings, one in the plane of the meridian, for observing the solstices, it is called a solstitial armil.
... of the human body, this anatomical school being the basis of a medical college for the education of physicians. For the astronomers Ptolemy Euergetes placed in the Square Porch an equinoctial and a solstitial armil, the graduated limbs of these instruments being divided into degrees and sixths. There were in the observatory stone quadrants, the precursors of our mural quadrants. On the floor a meridian line was drawn for ... — History of the Intellectual Development of Europe, Volume I (of 2) - Revised Edition • John William Draper
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