DEC 



DEC 



either between the plane and the prime 

 vertical circle, if you reckon it from the 

 east or west; or else between the meridi- 

 an and the plane, if you account it from 

 north or south. There are many ways 

 given by authors for finding the declina- 

 tion of a plane, of which all those that 

 depend upon the magnetic needle deserve 

 to be suspected on many accounts. The 

 common method, by finding the sun's ho- 

 rizontal distance from the pole of the 

 plane, is subject to many errors and dif- 

 ficulties. The way therefore we would 

 recommend, as the best for finding the 

 declination of a plane, is by a declinator. 



DECLINATOR, or DECLINATORY, an 

 instrument contrived for taking the de- 

 clinations, inclinations, and inclinations 

 of planes. See INSTRUMENTS, mathema- 

 tical. 



DECLINING dials, those which do not 

 face directly any of the four cardinal 

 points. See DIALLING. 



DECOCTION, the boiling of one, or 

 more ingredients in a watery fluid. See 

 PHARMACY. 



DECOMPOSITION, in chemistry. The 

 substance resulting from a chemical com- 

 bination is denominated a compound. 

 The substances of which it is formed are 

 called its constituent parts. When these 

 are again separated, the process is de- 

 nominated decomposition. See ANALY- 

 SIS. 



DECOUPLE, in heraldry, the same as 

 uncoupled : thus, a chevron decouple, is 

 a chevron wanting so much of it towards 

 the point, that the two ends stand at a 

 distance from one another, being parted 

 and uncoupled. 



DECOY, among fowlers, a place made 

 for catching wild fowl. A decoy is gene- 

 rally made where there is a large pond 

 surrounded with wood, and beyond that 

 a marshy and uncultivated country : if 

 the piece of water is not thus surrounded, 

 it will be attended with noises and other 

 accidents, which may be expected to 

 frighten the wild fowl from a quiet haunt, 

 where they mean to sleep in the day-time 

 in security. If these noises or distur- 

 bances are wilful, it has been held that 

 an action will lie against the disturber. 

 As soon as the evening sets in, the decoy 

 rises, and the wild-fowl feed during the 

 night. If the evening is still, the noise of 

 their wings during their flight is heard at 

 a very great distance, and is a pleasing, 

 though rather melancholy sound. 



The decoy ducks are fed with hemp- 

 seed, which is thrown over the screens 

 in small quantities, to bring them for- 



VOL. IV. 



wards into the pipes or canals, and to al- 

 lure the wild-fowl to follow, as this seed 

 is so light as to float. There are several 

 pipes, as they are called, which lead up a 

 narrow ditch that closes at last with a 

 funnel-net. Over these pipes (which grow 

 narrower from their first entrance) is a 

 continued arch of netting, suspended on 

 hoops. It is necessary to have a pipe or 

 ditch for almost every wind that can blow, 

 as upon this circumstance it depends 

 which pipe the fowl will take to ; and the 

 decoyman always keeps on the leeward 

 side of the ducks, to prevent his scent 

 reaching their sagacious nostrils. All 

 along each pipe, at intervals, are placed 

 screens made of reeds, which are so si- 

 tuated, that it is impossible the wild fowl 

 should see the decoyman before they have 

 passed on towards the end of the pipe, 

 where the purse net is placed. The in- 

 ducement of the wild fowl to go up one of 

 these pipes is, because the decoy ducks, 

 trained to this, lead the way, either after 

 hearing the whistle of the decoyman, or 

 enticed by the hemp seed ; the latter will 

 dive under water, whilst the wild-fowl fly 

 on and are taken in the purse. It often, 

 happens, however, that the wild-fowl are 

 in such a state of sleepiness and dozing 

 that they will not follow the decoy-ducks. 

 Use is then generally made of a dog that 

 is taught his lesson : he passes back- 

 wards and forwards between the reed 

 screens (in which are little holes, both 

 for the decoyman to see, and the little 

 dog to pass through ;) this attracts the 

 eye of the wild fowl, who, not choosing 

 to be interrupted, advance towards the 

 small and contemptible, animal, that they 

 may drive him away. The dog all the 

 time, by the direction of the decoyman, 

 plays among the screens of reeds, - nearer 

 and nearer the purse-net; till at last, 

 perhaps, the decoyman appears behind a 

 screen, and the wild-fowl, not daring to 

 pass by him in return, nor being able to 

 escape upwards on account of the net- 

 covering, rush on into the purse-net. 

 Sotn times the dog will not attract their 

 attention, if a red handkerchief, or 

 something very singular, is not put about 

 him. 



DECOY, in military affairs, a stratagem 

 to carry off the enemy's horses in a fo- 

 raging party, or from pasture. The 

 word is also used to denote a stratagem 

 employed by a small ship of war to be- 

 tray a vessel of inferior force into an in- 

 cautious pursuit, till she has drawn her 

 within the range of her cannon. It is 

 usually performed by painting the stern 



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