HYDRODYNAMICS Water Clocks Clepsydra

Description: Legend to the illustrations: HYDRODYNAMICS: WATER CLOCKS: Fig. 1. Earlier form of Clepsydrae or Water Clocks, 2. Another type of more ingenious construction, 3-4. Clepsydra invented by Ctesibius. FIG. 3-4. is probably the first machine to which toothed wheels were applied. Fig. 3. represents the outside of the machine, which consists of a cylinder sending upon a pedestal and of two figures of children, one of which allows the water to fall drop by drop from his eyes, while the other rises and indicates the hour with a wand upon the vertical line AB. The cylinder AB turns round its axis once in a year, and the inequality of the hours in different days is marked by the unequal distances of the horizontal carve lines on the surface of the cylinder. In Fig. 4, which shows the internal construction of the machine,, the water rises through the tube A into the figure of the infant on the right hand, and is discharged from its eyes into the square reservoir M, from which it passes, by a hole near M, into the pipe BCD. In this pipe a piece of wood floats upon the surface, and by its ascent, as the pipe fills, it raises the small pillar CD, on which the left hand figure is made to rest, so that the wand points to different hours as the float rises in the pipe. At the end of 24 hours the vessel BCD is filled, and also the arm FB of the inverted syphon FBE, which communicates with it. The water is therefore drawn off by the syphon, and falling in its descent into the buckets of the wheel K, it puts it in motion. This wheel has six buckets, and therefore performs a revolution in six days. Its axis carries a pinion N of six teeth, which works into the wheel I with 60 teeth ; and this wheel, carrying a pinion of ten teeth, drives the wheel GO with 61 teeth, which, by its axis OL, turns the pillar L once round in 366 days. . Print Specifics: Type of print: Copperplate engraving - original antique print Year of printing: not indicated in the print. The print came from the Edinburgh Encyclopedia published between 1808-1830 under the direction of Sir David Brewster. The last photo (not included in this offer) shows the publication schedule of individual volumes. Condition: 1 (1. Excellent - 2. Very good - 3. Good - 4. Fair). Overall Dimensions: 8 x 10.5 inches (20.5 x 26.5 cm). Paper weight: 3 (1. Thick - 2. Heavier - 3. Medium heavy - 4. Slightly heavier - 5. Thin)Reverse side: BlankNotes: 1. Green color border around the print in the photo is a contrasting background on which the print was photographed. 2. The print detail is sharper than the photo of the print. Martin2001 Satisfaction Guaranteed Policy! Any print purchased from me may be returned for any (or no) reason for a full refund including all postage. Internet seller since 1998.Five-star service.

Price: 18 USD

Location: Manassas, Virginia

End Time: 2025-01-17T01:18:01.000Z

Shipping Cost: 4.65 USD