TUMOR 



:>900 



TUNING FORK 



ered, arc carried or tumbled about by the wind, 

 like great, light balls. A* they scatter their - 

 about in their travels over the plains, they are 

 considered a pest by farmers and ranchmen. 

 Among the common American tumbleweeds are 

 the so-called Russian, thistle and two species of 

 pigweed. 



TUMOR, tu'mer, a word meaning swelling. 

 As commonly used it is applied to a growth in 

 the body which may be composed either of tis- 

 sues like those in which it is formed or of 

 unlike tissues. The former kind of tumor is 

 called bnu'f/n, or innocent, and the latter, ma- 

 lignant. Innocent tumors are usually not a 

 source of pain or discomfort, though they are 

 sometimes an inconvenience. They are re- 

 moved without danger, and do not return. Ma- 

 lignant tumors are painful, and are a source of 

 ill health. When removed they are liable to 

 return, and their tendency is to eat into sur- 

 rounding parts and to terminate fatally. See 

 CANCER. C.B.B. 



TUN'DRA, the Russian name for the ex- 

 tensive, low-lying, swampy plains of Siberia, 

 Europe and North America, bordering on the 

 Arctic Ocean. The surface is covered with a 

 dense growth of peat moss, which increases so 

 rapidly during the summer months, when the 

 marsh thaws for a depth of tw r o feet, that each 

 fall the ground has risen several inches in 

 height. During the short summer season wild 

 birds and fur-covered animals may be seen, 

 while flowering plants flourish in some parts. 

 The tundra cannot be crossed except in the 

 winter season, when the surface is hard. 



TUNG'STEN, a rare metallic element of a 

 grayish-white color, related to chromium (which 

 see). It is used to harden steel, in order to 

 make it a more suitable material for tools, and 

 drawn tungsten wire has an important place in 

 the manufacture of filaments for incandescent 

 lamps. Partinium, the alloy of tungsten and 

 aluminum, is employed in automobile manufac- 

 ture. The metal does not occur in a native 

 state, but is found in the rare minerals wolf- 

 ram, scheelite, stolzite and a few others. Its 

 atomic weight is 183.6; its symbol is W; and 

 its specific gravity, 16.6. 



TUNIC, tu'nik, from the Latin tunica, a 

 word having several applications, but most 

 closely associated with the dress of the ancient 

 Romans. The Latin tunic was an undergar- 

 ment worn by both men and women, and was 

 fastened about the waist by a belt or girdle. It 

 was covered by the toga, when worn by men, 

 and by the stola, when worn by women. The 



tunic of the Romans corresponded to the chiton 

 of the Greeks. Roman senators wore a tunic 

 having two broad stripes of purple down the 

 center (latus clavus), while the tunic of the 

 knights had two narrow stripes (angustus cla- 

 r^.s). Generals celebrating a triumph and 

 magistrates presiding at the games were dressed 

 in the- purple toga and a gold-embroidered tunic 

 (tunica palmata). 



Tunic, or tunicle, is also the name applied to 

 a vestment worn in the Roman Catholic and in 

 some Anglican churches by the subdeacon who 



THE TUNIC 



(a) The Doric tunic; (&) the Etruscan; (c) 

 the Phrygian. 



officiates at the celebration of the Mass. The 

 term is used somewhat locally to designate the 

 fatigue coat of a private in the British army. 

 At the present time, any loose, short garment, 

 fastened at the waist by a belt or girdle and 

 reaching from the neck to some distance above 

 the knee, is called a tunic. The term is heard 

 frequently in connection with the modern 

 gowns of women, and may refer to a sort of 

 overskirt of varying length. B.M.W. 



TUNING FORK, the invention of John Shore, 

 sergeant trumpeter to George I of England, is a 

 steel instrument having two prongs which, when 

 set in vibration, give forth a musical sound 

 varying in pitch according to the thickness of 

 the steel, the length of the prongs, or their dis- 

 tance apart. The ordinary tuning fork sounds 

 only one note, usually middle C or the A below 

 it, but some are made with a slide on each 

 prong, which, when moved up or down, regu- 

 lates the pitch of the note produced. The lat- 

 ter are of German construction. 



