given as a part of the regular course in the public schools.
Great wisdom should be exercised in selecting a site for a municipal bath-house, in order that it may accommodate as many as possible of those who most need it. The criticism has been made against English bath-houses that they are so situated and their appliances are so elaborate that they are chiefly patronized by a class who can well afford a private bath. A. Hessel Tillman, in a paper read before the Royal Institute of British Architects in February, 1899, emphasizes this fact, and proposes that a municipal bath department should embrace three types of bathing establishments: (1) The central establishments, containing swimming-pools for both sexes, as well as tub, shower, and hot-air baths; (2) the district bath and wash houses, to be much smaller, much nearer together, and located in the poorest and most crowded districts, each building containing not more than 50 shower baths, and from 30 to 50 washing compartments; (3) the people's baths, very small buildings, consisting of a series of double cells 6 × 3¼ feet, serving as dressing and washing compartments, the aim being to provide, in the simplest and cheapest manner, baths for the most crowded districts. The question whether or not a fee shall be charged is one much discussed by the advocates of municipal baths. It is contended that a slight fee encourages self-respect, and, on the other hand, that the establishment of even a small fee will debar that class who most need the baths. Many municipal baths, requiring fees, have free days, and make no charge for school children.
The modern appliance known as the 'rain' or 'shower' bath has done much to simplify the operation of the modern municipal bath-house. It requires less space, less water (11 instead of 50 or 60 gallons), and less attendance, and is therefore cheaper. It is also more sanitary, because cleanliness of the compartment is more easily maintained, and there is no danger of infection from the preceding occupant of the bath. There is also less danger that the bather will take cold.
A recent extension of free baths is their introduction into the public schools. This movement, like that for municipal baths in general, began in Germany, being established by Professor Flügge and Mayer Merkel in the schools of the German university town of Göttingen in 1885. Boston has introduced the institution into this country by constructing a number of public baths in the Paul Revere School, in the north end of the town, in 1900. It is proposed to extend the system to other Boston schools. Much is to be said in favor of this plan, where the school children come from the more crowded and unsanitary quarters, as attempts to keep school air pure by means of the most complicated appliances for ventilation will be futile until a higher standard of personal cleanliness is secured among certain classes of school children.
BATH'-KOL' (Heb., daughter of the voice, from bath, daughter + kol, voice). An expression which signifies simply a sound, and which is also used to designate an echo. Its specific application, however, in Rabbinical theology is to a manifestation of the divine will by means of a voice distinctly heard and announcing an order on the decision of some disputed point. It corresponds, therefore, to an oracle, only that the source of the voice is regarded as hidden. This usage of the term reverts ultimately to such a phrase as is found in Daniel (iv. 31): "A voice fell from heaven." Similarly in the New Testament, heavenly voices are referred to at the baptism of Jesus (Matt. iii. 17; Mark i. 11), at His transfiguration (Matt. xvii. 5; Mark ix. 7; Luke ix. 35), before the Passion (John xii. 28), and in the same way Paul and Peter hear voices from heaven. According to the views expressed in the Talmud, Bath-Kols were sent to Israel from time to time throughout its history, and numerous examples are instanced, and in theory such 'voices' were regarded as decisive factors after the extinction of divine prophecy in Israel. So it is reported that, as late as the days of Hillel and Shamnai, the differences between these two schools of interpretation of the Jewish law were decided by a Bath-Kol in favor of Hillel (Berichoth 3b) . In general, however, the tendency developed not to be guided by supposed 'voices,' and so that Bath-Kol came to be practically a term indicating the decision of a disputed question by rabbis whose authority was recognized. Consult: F. Weber, Jüdische Theologie, 2d ed. (Leipzig, 1897); Hamburger, Real-Encyklopädie für Bibel und Talmud, II. s. h. v. (Strelitz, 1883).
BATH (bath) MET'AL. An alloy of 9 parts of zinc to 32 of copper.
BATH'OLITE, Bathylite, Bathylith (Gk. βάθος, bathos, depth, or βάθύς, bathys, deep + λίθος, lithos, stone). A great, poorly defined mass of plutonic rock that affords evidence of having been formed far within the depths of the earth's crust during early periods of geological time, and of having attained its present condition of exposure at the surface through the agency of erosion. Such masses are common among rocks of the Achæan or pre-Cambrian Age, and often measure miles in extent. Evidence of the deep origin of batholites is furnished by the coarsely crystalline texture of the constituent rocks — a structure produced only by slow cooling and solidification at great depths in the crust. This hypothesis is also confirmed by the fact that such batholites appear to have been fused from below upwards, and to have incorporated within their mass portions of the overlying and surrounding rocks. See Igneous Rocks; and Pre-Cambrian Formations.
BATHOM'ETER, Gk. βάθος, bathos, depth + μέτρον, metron, measure). An instrument invented by C. Williams Siemens, for indicating the depth of the sea beneath a passing vessel. The density of sea-water is about 1.026, while that of solid earth or rock has an average of about 2.75. Hence, the attraction of the water which lies beneath the ship is less than that which would be exerted by earth or rock occupying the same relative position, and the greater the depth of water, the less the attraction. The weight of a given mass on board the ship will be greater, therefore, when the ship is in a harbor or in shallow water than when on the deep sea by an amount which may be determined by an instrument of sufficient delicacy, and this change in weight becomes a recognizable function of the depth of water. Dr. Siemens filled with mercury a vertical steel tube of small bore, fitted below with a cup-shaped expansion closed with a
