CIRCULATION (in Anatomy.) The country of Palestine. There were some like. natural motion of the blood in a living ani- wise in cities and private houses. As the mal, whereby it proceeds from the heart to cities most part were built in moun all parts of the body by the arteries, and re- tains, and the rains fell regularly in Judea at turns to the heart by the veins. two seasons of the year only, in spring and CIRCUMFERENCE. The curve line autumn, people were obliged to keep water in which bounds a circle. their cisterns in the country for the use of CIRCUMFERENTOR. An instrument their cattle, and in cities for the convenience used by surveyors for taking angles. It is an instrument (where great accuracy is not de- CITRIC ACID. The acid of limes, or sired) much used in surveying in and about woodlands, commons, harbours, sea coasts, CITRON. A species of the lemon, which in the working of coal mines, &c. &c. is much cultivated in Persia and the warm Where a permanent direction of the needle is of the most material consequence in survey ing, the instrument is made of brass, and in its most simple state consists of the following parts : A brass index and circle all of a piece.
The index is commonly about 14 inches long, and an inch and a half broad, the diameter of the circle about seven inches. On this is made a chart whose meridian line answers to the middle of the breadth of the index, and is divided into 360 degrees. There is a brass ring soldered on the circumference of the circle, on which screws another ring, with a flat glass in it, so as to form a kind of box for the needle, suspended on the pivot in the cen tre of the circle. There are also two sights to screw on and slide up and down the index, as also a spangle and socket screw on the lack of the circle for putting the head of the stall in ference by half the diameter, or the diameter by 0.7853932. In practical mathematics, every circle is supposed to be divided into 360 parts or degrees. A E and D B are diameters; A D and B E are arcs; A C D is an acute angle; and D C E an obtuse angle.