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1938. Type. woodcut. Dimensions. 43.5 cm × 43.9 cm (17.1 in × 17.3 in) Sky and Water I is a woodcut print by the Dutch artist M. C. Escher first printed in June 1938. The basis of this print is a regular division of the plane consisting of birds and fish. Both prints have the horizontal series of these elements —fitting into each other like ...
A wing-clipped Meyer's parrot perching on a drawer handle. While clipping is endorsed by some avian veterinarians, others oppose it. [7]By restricting flight, wing clipping may help prevent indoor birds from risking injury from ceiling fans or flying into large windows, but no evidence shows that clipped birds are safer than full-winged ones, only that clipped birds are subject to different ...
A fish can have up to three dorsal fins. The dorsal fins serve to protect the fish against rolling, and assist it in sudden turns and stops. The bones that support the dorsal fin are called pterygiophores. There are two to three of them: " proximal " (axonosts), "middle" (baseosts), and " distal ".
The cut-throat finch has plumage that is pale, sandy brown with flecks of black all over. It has a black-brown tail, a thick white chin and cheeks, and a chestnut brown patch on the belly. The legs are a pink fleshy colour. The adult male has a bright red band across its throat (thus the name "cut throat"), while the male juveniles have a ...
Memorial anchor in Kirjurinluoto, Pori, Finland. Massive anchor chain for large ships. The weight of the chain is vital for proper holding of the anchor. [1] An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current.
Tool use by non-humans is a phenomenon in which a non-human animal uses any kind of tool in order to achieve a goal such as acquiring food and water, grooming, combat, defence, communication, recreation or construction. Originally thought to be a skill possessed only by humans, some tool use requires a sophisticated level of cognition.
The "aerial screw" was one of several aerial machines drawn by Leonardo, including an early parachute, an ornithopter and a hang glider . The pen-and-ink sketch outlines an idea for a flying machine similar to a modern helicopter, with a spiral rotor or "aerial screw" based on a water screw, but intended to push against the fluid of the air ...
Robertson screw. A Robertson screw, also known as a square screw[1] or Scrulox, [2] is a type of screw with a square -shaped socket in the screw head and a corresponding square protrusion on the tool. Both the tool and socket have a slight taper. The contemporary square drive screw has all but replaced the Robertson screw proper and is commonly ...