TRIGONOMETRY 



5879 



TRILLIUM 



shaped bay called the Gulf of Trieste. The 

 city is about seventy-three miles, northeast of 

 Venice and 367 miles southwest of Vienna (see 

 map, following page 2092). It is the capital of 

 'the province of Kiistenland, and with surround- 

 ing territory constitutes a crownland about 

 forty square miles in area. Trieste is an impor- 

 tant coaling and supply station for the Austrian 

 navy, and possesses a naval arsenal. There are 

 two sections to the city the oid town with 

 steep, narrow streets, clustered about the 

 Schlossberg (Castle Hill), and the new portion, 

 on the flats along the bay. The Corso, the 

 city's busiest thoroughfare, divides" these two 

 sections. Conspicuous features of Trieste are a 

 group of new municipal buildings, a nautical 

 academy, several museums, the public gardens, 

 an observatory, a public library of over 120,000 

 volumes, the magnificent offices of the Austrian 

 Lloyd, the most important shipping firm, and 

 several handsome churches and public squares. 



The harbor is spacious and up-to-date, and 

 docking facilities are increased by the Canal 

 Grande, which enters the city north of the 

 Corso. In normal years over 14,000 vessels 

 clear the harbor annually. Besides naval stores 

 and ships, manufactures include marine steam 

 engines, furniture, beer and wine, soap, clothing 

 and textiles. During the War of the Nations 

 (which see) Trieste was on several occasions 

 bombarded by airships, and it was the objective 

 point of the great Italian drive under General 

 Cadorna, in the summer and fall of 1917. In 

 September the Italian forces penetrated to 

 within a dozen miles of the city. In 1910 the 

 population of the city was 160,993; of the 

 former Austrian crownland, 229,510. The peo- 

 ple are largely Italians. 



TRIGONOMETRY, trig o nom' e in, a branch 

 of mathematics having to do with the measure- 

 ment of triangles and with the relations of their 

 sides and angles to one another. It follows 

 geometry in the regular course of study and 

 depends upon certain truths there demon- 

 strated: that the sum of the angles of a tri- 

 angle is always equal to two right angles; and 

 that, if three parts of a triangle, at least one of 

 which is a side, be known, the remaining parts 

 may be computed. 



The two chief divisions of trigonometry are 

 'plane, and spherical. Plane trigonometry treats 

 of such angles as lie wholly in a plane, and 

 spherical trigonometry of angles that lie upon 

 the surface of a sphere. To facilitate the com- 

 putations to which operations in trigonometry 

 give rise, tables of logarithms (which see) have 



been prepared. They were added to the science 

 by Napier in the seventeenth century. 



The practical uses of trigonometry are many 

 and important. Plane trigonometry, for ex- 

 ample, is used extensively in astronomy, phys- 

 ics and engineering, and spherical trigonometry 

 is used in astronomy and in measuring long dis- 

 tances on the surface of the earth, where its 

 curvature must be taken into consideration. 

 In surveying, the science is used in determining 

 distances and in measuring the height of moun- 

 tains and other lofty objects. 



TRILLIUM, tril'ium,or WAKE-ROBIN, the 

 names of several species of plants belonging to 

 the lily family, so called because their flower 

 parts are in threes and because they frequently 

 bloom early in the spring, in time to "wake" 



THE PAINTED TRILLIUM 



the robins. They are among the loveliest of 

 the early wild flowers. The trilliums have three 

 sepals, three petals, two times three stamens 

 and three styles, and each flower blossoms from 

 a cluster of three leaves. Dwarf trillium bears 

 its solitary, pure white flower at the end of a 

 stem not over six inches high. This stem rises 

 from a small, tuberlike rootstock, said to be 

 poisonous. Large- flowered trillium has flower 

 petals two inches or more in length; though 

 white at first, the blossoms generally become 

 rose-colored later in the season. More striking 

 than either of these is the painted trillium, 

 whose wax-white petals have stripes of wine or 

 deep pink. The fruit of the trilliums is a red 

 berry. These flowers are found usually in moist 

 woodlands. 



