SCIENCE, INVENTION, DISCOVERY. 



327 



have both been used by the British army in their 

 Eastern campaigns. The instruments differ 

 somewhat in construction, but the result arrived 

 at is the same in both. Signals are produced by 

 causing a reflected ray of the sun to appear 

 and disappear alternately at a distant point, 

 the intervals of appearance and obscuration 

 being carried in length so as to produce the 

 combination of long and short signals, known 

 as the Morse alphabet. The reflecting body is 

 a glass mirror which varies in size according 

 to the distance to which it is desired to signal. 

 A five inch mirror has given, when atmos- 

 pheric conditions were favorable, distinct sig- 

 nals at a distance of sixty miles. The helio- 

 graph has also been found of great service in 

 defining distant points for large surveys, and 

 was used for verifying the arc of the meridian 

 by the astronomers at the Cape of Good Hope. 



Horse Power of Steam Engines. 

 The unit of nominal power for steam engines, 

 or the usual estimate of dynamical effect per 

 minute of a horse, called by engineers a " horse 

 power," is thirty-three thousand pounds at a 

 velocity of one foot per minute, or, the effect 

 of a load of two hundred pounds raised by a 

 horse for eight hours a day, at the rate of two 

 and a half miles per hour, or 150 pounds at 

 the rate of 220 feet per minute. 



RULE Multiply the area of the piston in 

 square inches by the average force of the 

 steam in pounds and by the velocity of the pis- 

 ton in feet per minute ; divide the product by 

 thirty-three thousand, and seven tenths of the 

 quotient equals the effective power. 



Human Family, The The three pri- 

 mary divisions of man, as indicated by Latham, 

 are the Indo-European, the Mongolian, and 

 the African. 



I. THE INDO-EUROPEAN OR CAUCASIC 

 race originally extended from India across 

 Europe, and, increasing ever in civilization and 

 intellectual power from age to age, has become 

 the dominant one in the world, extending its 

 influence to every part of the earth, supplanting 

 many inferior races, and repeopling wide 

 areas, as in America and Australia. 



The Caucasic race comprises two principal 

 branches the Aryan and the Semitic. A 

 third branch, according to M. de Quatrefages, 

 includes the Caucasians proper, Euscarians 

 (Basques), and others. 



Most of the inhabitants of Europe belong to 

 the Aryan Family ; they are arranged in the 

 following groups : 



1. The Keltic, in the N. W., comprising 

 the Welsh, Gaels, Erse, Manx, and Armor- 

 icans. 



2. The Italic, chiefly in the S. W. and S., 

 comprising the Italian and other Romance 



nations French, Spanish, Portuguese, Rou- 

 mariesch, and Roumanians. 



3. The Thraco-Hellenic, in the S. E., 

 Greeks, and Albanians. 



4. The Teutonic, in the N. N. W. and 

 center, comprising the Germans, Scandina 

 vians, Danes, Icelanders, Dutch, Flemings, 

 English. 



5. The Lithuanian, S. E. of the Baltic. 



6. The Slavonic, in the E., comprising the 

 Russians, Poles, Tsekhs, Serbs, Croats, Bul- 

 garians, etc. 



The Indo-European or Caucasic race in Asia 

 comprises the Hindoos, Baluchis, Afghans, Ir- 

 anians (Persia), Galchas (Zarafshan), and the 

 Semitic tribes of Armenia, Syria, Arabia, etc. 



II. THE MONGOLIAN is divisible into three 

 branches, according to geographical position, 

 which again form numerous smaller families. 



1. The Asiatic, comprising the Mongolians 

 of the Chinese Empire, India, and Indo-China ; 

 the Kalmucks, adjoining the Turks, who ex- 

 tend from Southern Europe far into Central 

 Asia ; the Magyars of Hungary ; the Yakuts 

 and Samoeids (or Samoyedes) of Siberia ; with 

 the Lapps, Finns, and various tribes of East 

 Europe. 



2. The Oceanic Mongolians are composed 

 of two classes. 1. The black-skinned found 

 in New Guinea, Australia, Tasmania, and the 

 islands between New Zealand, and New Cale- 

 donia. II. The yellow, olive, or brown race, 

 occupying New Zealand, the Malay Peninsula, 

 Sumatra, Borneo, Java, Moluccas, Philippines, 

 Madagascar, etc. 



3. The American Mongolians comprise a 

 large number of tribes, the chief of which in 

 North America are the Athabaskans, Algon- 

 kins, Sioux, Paducas, and Mexicans. In South 

 America, the Quichuas, Chilians, and Pata- 

 gonians extend along the west coast. The 

 Caribs, Maypures, Brazilians, Moxos, and 

 Chiquitos occupy the north, east, and center 

 of the continent. The Eskimos form a con- 

 necting link between the Asiatic and American 

 branches of this family. 



III. THE AFRICAN, forming the third great 

 division of the human race, is exhibited in its 

 purest form by the natives of Western Africa. 

 The Negroes occupy the whole central portion 

 of the country from Cape Verde on the west 

 to Khartoom on the east, and south to the 

 Congo. South of the Negroes are the Bantus 

 (including the Kafirs), inhabiting the greater 

 part of Africa between the 4th parallel of N. 

 lat. and the Cape. In the S. W". are the Hot- 

 tentots. Certain dwarfish tribes are found in 

 different parts of the continent, as the Bush- 

 men of the Kalahari Desert, the Obongo of 

 Ogowe basin and others. Tfoe Fu,las, and Nu,- 



