CENTRAL FIRE CENTRE. 



125 



mercial respect, as the navigable river S. Juan unites 

 it to the Atlantic ocean, and a canal has been pro- 

 posed for connecting the Atlantic and Pacific oceans, 

 to receive its water from this lake. There are seve- 

 ral volcanoes on its shores. The aboriginal popula- 

 tion of the country has very much decreased. The 

 ruins of Huehuetlapallan (q. v.) are remarkable. 

 The converted Indians are called Ladinos ; the 

 others, Barbaras, or Bravos. Two pieces of land 

 (Tagurgalpa and Tolagalpa), belonging to the 

 United Provinces, have never been subjected by the 

 European settlers, or their descendants, and are in- 

 habited by the independent Moscos, or Mosquitos, 

 and other tribes. That part of the coast called the 

 Mosquito coast, and extending to cape Gracias-a-Dios, 

 the congress at Colombia, in 1824, declared to be- 

 long to the territory of Colombia. A part of that 

 coast called Poyais (q. v.), containing a town of the 

 same name, was erected into a separate state by the 

 Scotch adventurer, Mac Gregor. 



Central America contains antiquities of a very in- 

 teresting nature, which have been but imperfectly 

 examined and described hitherto, and which indicate 

 that the aboriginal inhabitants of the country had 

 even attained a very respectable proficiency in the 

 knowledge of the arts of life. Near the village of 

 Palenque are the ruins of what was once a city of 

 several leagues in circumference. Remains of tem- 

 ples, altars, and ornamental stones, statues of deities, 

 and other works of sculpture, are permanent proofs 

 of its former importance. Like remains are found 

 near Ocosingo, in the same part of Central America. 

 A circus, and several stone pyramids, in the valley 

 of Copan, in Honduras, are better known than the 

 nuns of Palenque and Ocosingo. Vestiges of the 

 city of Utatlan, before mentioned, of Patinamit and 

 Mixco, and of many fortresses and castles in the 

 province of Quezaltenango, are mentioned by Juarros 

 and other authors. 



This country has attracted attention incidentally 

 of late, owing to its geographical position, and the 

 hope entertained by many of seeing a canal cut across 

 the isthmus in some part of Central America, so as 

 to unite the Pacific and Atlantic oceans by a navi- 

 gable channel. It has been well described by a 

 native, Domingo Juarros, whose account has been 

 translated into English by Mr Baily Statistical and 

 Commercial History of Guatimala. See also don 

 Francia de Fuente's History of Guatimala, before and 

 after the Spanish Conquest. 



CENTRAL FIRE. Many natural philosophers 

 have supposed a perpetual fire to exist in the centre 

 of the earth, which they call central fire. In ancient 

 times, volcanoes and other similar phenomena were 

 explained by it. At a later period, when it was un- 

 derstood that such a fire in the interior of the earth 

 was impossible, the phrase was used to express the 

 interior warmth of the earth. To this central warmth 

 Mairan ascribes a great part of the warmth on the 

 surface of the earth. To a certain depth, there 

 appears to be a fixed temperature in the interior of 

 the earth, which probably arises from the penetrating 

 heat of the sun. At least experiments show that in 

 hot climates the interior of the earth is warmer than 

 in cold ones. In Siberia, for instance, some work- 

 men, having penetrated eighty feet in digging a well, 

 found the earth frozen even at that depth. Interest- 

 nig information on this subject may be found in Biot's 

 Astronomie Physique (2d ed., Paris, 1810), in the 2d 

 vol. 15th chap. De la Temperature de la Terre. 



CENTRAL FORCES. When a stone is made to 

 revolve round the hand in a sling, it has a continual 

 tendency to fly off in a straight Tine, which is coun- 

 teracted by the string which draws the stone to the 

 liand. The string acts as a centripetal force, by con- 



stantly drawing the revolving body to the centre of 

 motion ; but the moment that the string is let go, or 

 breaks, the stone will fly off in a right line, in conse- 

 quence of its centrifugal force. When both forces 

 are spoken of together, they are called central forces. 

 The centripetal force of a body revolving round a 

 fixed centre, may either be the cohesion of the par- 

 ticles of which that body is composed, as is the case 

 in a grindstone revolving on its axis ; or it may be 

 the influence of some attracting power, as gravity, in 

 the case of the planets. So long as the revolving 

 body retains its curvilinear path, the central forces 

 counteract each other, and are therefore equal ; so 

 that, when the value of the one is found, that of the 

 other is also determined. The central forces are as 

 the radii of the circles in which the bodies move, di- 

 rectly or inversely, as the squares of the times of revo- 

 lution ; and the squares of the times are as the cubes 

 of the distances of the bodies from the centre of 

 motion. By these laws we may determine the rela- 

 tive intensities of central forces ; and as to the actual 

 measure of these forces, it may be shown, that the 

 actual velocity of a body moving in a circle is the 

 same as it would acquire by falling through a dis- 

 tance equal to one-fourth of the diameter, by the 

 constant action of the centripetal force. In conse- 

 quence of the action of these laws, there is a limit to 

 the magnitude and velocity of revolving bodies. 

 Thus, if the fly-wheel of a steam engine, the weight 

 of whose rim is one ton, revolve at the rate of fifty- 

 three revolutions in a minute, it will, by reason of 

 the predominance of the centrifugal force over the 

 cohesion of the cast metal, burst asunder ; and the 

 same laws put a limit to the height of edifices erected 

 upon the surface of the earth ; for the velocity of the 

 top of a tower carried to a certain height would be 

 so great, that the strength of the hardest stone, or 

 most tenacious cement, would be overcome. With 

 regard to the heavenly bodies, it is supposed that the 

 Creator impressed them originally with,a power to 

 move on eternally, in one direction, by their inertia ; 

 but, by the action of gravity, the line of this direction 

 is continually changing, the planets being all attracted 

 to the centre of the system. See Circular Motion. 



CENTRAL MOTION. See Circular Motion. 



CENTRE, LE (French; signifying the centre). 

 In the French chamber of deputies, the seats are 

 ranged in a semicircle in front of the president, and 

 leave only a narrow passage in the centre. The 

 ministers themselves do not sit, as in England, among 

 the deputies, but in the front seat, on the left side of 

 the centre. In England, the ministry is the centre 

 of the majority, and all who do not vote with it, 

 however different their views, unite in the opposition. 

 In France, the two chief parties, one of which is 

 attached to the old, the other to the new system of 

 things, are opposed to each other independently of 

 the ministers, and thus enable the ministry to main- 

 tain itself, as has been the case till very lately, 

 without belonging decidedly to either party. The 

 ministry bestows many offices on the condition that 

 the officers shall always vote with it. In the French 

 chamber of deputies, the adherents of the ministry 

 chiefly sit near their leaders, on the seats in the 

 centre (le centre). Here are to be found, therefore, 

 the prefects, state-attorneys, and other officers of the 

 government, who, for the sake of office, support all 

 the propositions of the ministers. But private opin- 

 ion, and the circumstances by which it is influenced, 

 often operate so powerfully, that parties even appear 

 in the centre. It is itself divided into a right and left 

 side. In England, the members of the parliament 

 also sit on different sides, according to their party. 

 In the United States of North America, the seats 

 are decided by lot, in both houses, and thus the 



