area of about 184 square miles. This lake is remarkable because in winter the northern part is frozen so as to bear sledges, while the southern part has never been known to freeze.
AL'TITUDE (Lat. altitudo, height, from altus, high, lofty). In astronomy, the elevation of a heavenly body above the horizon. It is measured not as a linear distance, but by the angle which a line drawn from the eye to the heavenly body makes with the horizontal line, or by the are of a vertical circle intercepted between the body and the horizon. Altitudes are measured by means of a telescope attached to a graduated circle. (See Circle.) The telescope being directed toward the body to be observed, the angle which it makes with the horizon is measured on the graduated circle. The altitude thus observed must receive various corrections — the chief being the parallax (q.v.) and refraction (q.v.) — in order to get the true altitude. At sea, the altitude is taken by means of a sextant (q.v.), and then it has further to be corrected for the dip of the visible horizon below the true horizon. (See Horizon.) The correct determination of altitudes is of vital importance in the problem of navigation. The sextant is' the only astronomical instrument of precision that can be used without a fixed support on the deck of a rolling ship, and it is essentially an instrument for measuring altitudes. See Sextant; Altazimuth; Latitude.
ALTMÜHL, iilfmul (Ger., old mill).
A tributary of the Danube, rising at the western border of Bavaria, flowing northeast through the Swabian Jura, and joining the Danube at Kelheim (Map: Bavaria, D 4). It is 100 miles long, and connected with an affluent, the Main, by the Ludwig's Canal.
ALTO (Ital., high). The deepest or lowest species of voice met with in boys or castrates, the voice of women being more properly called contralto. In England the alto voice is often found in adults, especially among the ballad singers; the head notes are carefully developed to abnormal volume and power at the expense of the lower notes, which gradually become atrophied and assume the same timbre as the upper register. It is curious that the original name altus meant the highest voice in ecclesiastical music. It represented the changing, undulating melody sung over the cantus firmus (q.v.), but owing to its difficulty, it could not be learned by boys, and thus to men with the highest voices was assigned the part, as women were excluded from church choirs — mulier taccat in ecclesia — i.e., let women be silent in the church.
ALTON, al'ton.
A city and railroad centre of
Madison Co., Ill. It is picturesquely situated on
limestone bluffs, 200 feet above the Mississippi
River, which is spanned here by the great bridge
of the Chicago, Burlington and Quincy Railroad,
25 miles above St. Louis (Map: Illinois, B 5).
It is on the Chicago and Alton and other rail-
roads, is the centre of a large commerce. and has
glass factories, flouring mills, machine shops,
agricultural and mining tool factories, box f.ae-
tories, etc. .lton has a public library and a park,
called Rock Spring Park. .t LTpper Alton is
Shurtlefl' College (Baptist), organized 1827, and,
at Godfrey, the Montioello Seminary. Alton was
settled in 17S.3, incorporated in 1835. and is gov-
erned by a charter granted under a general law
of 1876. The mayor is elected for two years;
the city council is made up of fourteen members, and town meetings are held yearly to levy the town tax and approve the supervisor's report. The mayor appoints the school board and the heads of the police and fire departments, with the approval of the council. On November 7, 1837, occurred here the famous anti-abolitionist riot, in which Elijah P. Lovejoy was killed and his printing-office demolished. Pop., 1890, 10,294; 1900, 14,210.
ALTON (al'ton) LOCKE, TAILOR AND POET. A novel by Charles Kingsley, published 1850.
ALTON, Johann Samuel Eduard d' (1803-54). A German anatomist, son of the anatomist and archæologist Joseph Wilhelm Eduard d'Alton. He studied medicine at Bonn, and became professor of anatomy at the Academy of Arts in Berlin in 1827. In 1834 he was made professor of anatomy and physiology at Halle. His writings include: Handbuch der menschlichen Anatomie (Leipzig, 1848-50), De Monstris (Halle, 1853), and De Monstrorum Duplicium Origine (Halle, 1849).
ALTONA, iil'tfi-na. The largest and richest
city in the Prussian province of Schleswig-Hol-
stein, situated on the right bank of the Elbe, its
eastern boundary adjoining the Hamburg suburb
of St. Pauli (Map: Prussia, C 2). From a
commercial point of view, Altona forms one city
with Hamburg. In 1888 it entered the German
Customs Union. On account of its advantageous
situation on the Elbe and railway connection
with other German cities, its trade is of con-
siderable importance, and extends to England,
France, the Jlediterranean Sea, and the West
Indies. There are manj' important industrial
works in Altona, among others, cotton and wool-
en mills, iron foundries, glass works, breweries
and distilleries, and establishments for the manu-
facture of chocolate, cigars, cotton, soap, leather
ware, etc. Local transportation is afforded by
numerous street-car lines, which also connect
Altona with Hamburg. These are all in the
hands of private corporations. The rise of .41-
tona to its present importance has been recent,
and rapid for a Continental town. In 1880 its
population was 91,000, from which it had grown
to 143,000 in 1890 and to 155,000 in 1900.
The streets of Altona are broad and for the most part regular, and well lighted by electricity. The city has only about fifty acres laid out in parks. This, however, does not include the suburbs. Among the notable buildings may be mentioned the Rathaus, the palace of justice, the custom house, and the city theatre. Among the objects of greatest interest in the city is the old cemetery of the Portuguese Jews.
The city's affairs are administered by a municipal council composed of 35 members, and an e.xecutivc board composed of nine members. (See Prussia, paragraph Government.) The street-cleaning of Altona is a model of thoroughness. The city owns its water works, containing a filtering plant by means of which the water of the Elbe is purified for drinking ])urposes. The plant yields an annual profit of about $90,000. Its system of sewers is practically similar to that of Hamburg. It has not as yet adopted the system of sewage farms, vhieh has proved so successful in some of the German cities. The annual expense of drainage and sewerage is about $12,000.
