CON 



CON 



that every man undertakes to perform : 

 thus, if a man take up wares from a 

 tradesman without any agreement of 

 price, the law concludes that he contract- 

 ed to pay their real value. 



CONTRACT, vniriout, is an agreement 

 to p*\ more interest for money than the 

 laws allow. 



CONTRACTION, in physics, the dimi- 

 nishing the extent or dimensions of a bo- 

 dy, or the causing its parts to approach 

 nearer to each other, in which sense it 

 stands opposed to dilatation o"r expansion. 

 See EXPASSIOX. 



Water and all aqueous fluids are gra- 

 dually contracted by a diminution of tem- 

 perature, . until they arrive at a certain 

 point, which is about 8 above the freez- 

 ing point ; but below that point they be- 

 gin to expand, and continue to do so ac- 

 cording as the temperature is lowered. 

 Similar effects have been observed with 

 regard to some metals. Speaking of con- 

 traction, a remarkable phenomenon, of 

 considerable importance in manufactures, 

 obtrudes itself on our notice. It is the 

 hardness which certain bodies acquire in 

 consequence of a sudden contraction, and 

 this is particularly the case with glass 

 and some of the metals. Thus glass 

 vessels, suddenly cooled after having 

 been formed, are so very brittle, that 

 they hardly bear to be touched with any 

 hard body. The cause of this effect is 

 thus properly explained by Dr. Young. 

 "When glass in fusion is very suddenly 

 cooled, its external parts become solid 

 first, and determine the magnitude of the 

 whole piece, while it still remains fluid 

 within. The internal part, as it cools, is 

 disposed to contract still further, but its 

 contraction is prevented by the resistance 

 of the external parts, which form an arch 

 or vault round it, so that the whole is left 

 in a state of constraint ; and as soon as 

 the equilibrium is disturbed in any one 

 part, the whole aggregate is destroyed. 

 Hence it becomes necessary to anneal all 

 glass, by placing it in an oven, where it is 

 left to cool slowly ; for, without this pre- 

 caution, a very slight cause would de- 

 stroy it. The Bologna jars, sometimes 

 called proofs, are small thick vessels, 

 made for the purpose of exhibiting this 

 effect ; they are usually destroyed by the 

 impulse of a small and sharp body ; for 

 instance, a single grain of sand, dropped 

 into them ; and a small body appears to 

 be often more effectual than a larger one, 

 perhaps because the larger one is more 



liable to strike the glass with an obtuse 

 part of Us surface." 



CONTRA harmonica! proportion, in arith- 

 metic, is that relation of three terms, 

 wherein the difference of the first and se- 

 cond is to the difference of the second and 

 third as the third is to the first : thus, 3, 5, 

 and 6, are numbers contra-harmonically 

 proportional, for 2 : 1 :: 6 : 3. 



CONTRAST, in architecture, is to 

 avoid the repetition of the same thing, in 

 order to please by variety. 



CONTRATE -wheel, in watch-work, 

 that next to the crown, the teeth and 

 hoop whereof lie contrary to those of the 

 other wheels, from whence it takes its 

 name. 



CONTRATALLATION, or the line of 

 contravallation, in fortification, a trench 

 guarded with a parapet, and usually cut 

 round about a place by the besiegers, to 

 secure themselves on that side, and to 

 stop the sallies of the garrison. See 

 FORTIFICATION-. 



CONTRAVENTION, in law, a man's 

 failing to discharge his word, obliga- 

 tion, duty, or the laws or customs of 

 the place. The penalties imposed in cases 

 of contravention only pass for commina- 

 tory. 



CONTRAVENTION, in a more limited 

 sense, signifies the non-execution of an 

 ordinance or edict. It is supposed to be 

 the effect of negligence or ignorance. 



CONTRA YERVA. See MATEHIA ME- 



PICA. 



* -CONTRE, in heraldry, an appellation 

 ' given to several bearings, on account of 

 their cutting the shield contrary and op- 

 posite ways : thus we meet with contre- 

 bend, contre-chevron, contre-pale, &c. 

 when there are two ordinaries of the 

 same nature opposite to each other, so as 

 colour may be opposed to metal, and 

 metal to colour. 



CONTRIBUTION, in a general sense, 

 the payment of each person's quota, or 

 the share he bears in some imposition or 

 common expense. Contributions are 

 either voluntary, as those of expenses for 

 carrying on some undertaking for the 

 public interest, or involuntary, as those 

 of taxes and imposts. 



CONTRIBUTION, in a military sense, an 

 imposition or tax paid by frontier coun- 

 tries to an enemy, to prevent their being 

 plundered and ruined by him. 



CONTROLLER, an officer appointed 

 to control or oversee the accounts of 

 other officers, and, on occasion, to cer- 



