TECHNICAL INDEX AND GLOSSARY 



tant objects appear near, the invention of the Dutch optician 

 Lippershey in the seventeenth century. In 1609 Galileo invented 

 another type of telescope for astronomical observations. See 

 Vol. II, p. 77. For later improvements in telescopes, see "In- 

 struments of Precision in the Age of Newton," Vol. II, p. 252. 



Telluric Structure. Pertaining to the structure of the earth. 

 See "Solar and Telluric Problems," Vol. V, p. 205. 



Telpherage Systems. The invention of Fleeming Jenkin, which 

 consists of overhead cables hung on poles along which carriers 

 of small capacity are hauled by electric motors. See "Traction 

 in Mining," Vol. VI, p. 256. 



Tetanus. The disease commonly known as lockjaw, is 

 characterized by spasm of the voluntary muscles. It is caused 

 by the tetanus bacillus, which was discovered by Nicolaier in 

 1884. Behring discovered an antitoxic serum which averts the 

 attack of the disease when administered in time. See "Serum- 

 therapy," Vol. IV, p. 240. 



Textiles. Materials made by weaving together of threads to 

 form a nearly solid surface, such as cloth, rugs, etc. The term 

 does not apply to substances woven of wood, such as baskets. 

 See "The Manufacture of Textiles," Vol. IX, p. 38. 



Thermometer. A familiar instrument for determining the 

 temperature. The most common form is that of an exhausted 

 closed glass tube in which a column of mercury expands and 

 contracts. The two kinds in more common use are the Centi- 

 grade, the freezing point of which is o, and the boiling point 

 100; and the Farenheit, the freezing point of which is 32, the 

 boiling point 212. 



Thorium. An element discovered by the Swedish chemist 

 Berzelius, and named by him after the ancient Scandinavian god 

 Thor. It is one of the most valuable of the rare elements. The 

 oxide of thorium is used in the preparation of gas mantles. See 

 "The Incandescent Gas Mantle," Vol. VI, p. 208. 



Toxine. Substances, generally of bacterial origin, which, when 

 brought into the circulation, produce diseases of a distinct nature 

 according to the nature of toxine. See "Serum-therapy," Vol. 

 IV, p. 240. 



Transformers. In electricity, are mechanisms for transform- 

 ing a current of a certain voltage into one of higher or lower 

 voltage. A "step-up" transformer changes a current of low 

 voltage to one of higher voltage; a "step-down" transformer acts 



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