673 



THERMOMETER. 



stndenta, a library of 7800 volumes, and real estate ' strument, Fahrenheit's scale is formed thus: The 



worth $50.000. .1. M Atwood. 1> !>.. is at its head. 



Tiiflt Collrgf, at Oollan Hill. Max., has a I'ivinity 

 School which was opened IN, '.i. and made rapid pro- 

 jrress. Prs. T. .J Sawyer and ('II Ix'onard were i In- 

 first professors. In 1875 a four use was pro- 

 vided for non -graduates, and the faculty iner. , 

 IK>W numbers 7 professors and instructors. H. ll.C.ipen. 

 D. D-, is president. There are 34 students and about 

 100 gradii 



Lnmf^inl L'nirrniti/. (ialeshunr. 111., has a th 

 ca.1 department o|>encd lss| It reports 7 teachers 

 and 11 students under N. White. 



UNDKNOMINATKINAU 



ml I'lii'rfrxi'tt/. at Washington, D. C., opened 

 1870, has a theoloiri -a! department under J. C. Craig- 

 head, with 5 teachers and 53 students. 



J KWISH. 



The Ilrbmn I'ninn t'ullfgf, at Cincinnati, Ohio, was 

 organized 1875. It has t teachers. :;_: pupils, 95UO 

 volumes, and real estate worth $30,000. J. M. Wise 

 is at its head. 



From the above statistics it will appear that theo- 

 loji -al seminaries, no less than colleges, multiply be- 

 yond any very pressing demand for their sen 

 at least beyond the power and will to sustain them. 

 It is a common remark that a moderate number of 

 strong institutions would be better than a plethora of 

 feeble ones. But the American tendency is to bring 

 education, professional as well as general, as near as 

 possible to every man's door, and in the strife of sects 

 each wishes to be represented, as nearly as it can, in 

 every part of the country. The moral is obvious, but. 

 is usually unheeded. With several of the denomina- 

 tions one-third or more of their schools might be 

 wiped out without special injury, and this process is 

 not unlikely to take place t .:cnt. (K. M. II.) 



THEKMO. \1KTKR. This familiar instrument for 

 HM>V XVIII determining the temperature of air or 

 i 28*8 (D 308 otm ' r fl"' 1 ' ls "'U'dly filled with mer- 

 Am Rep ) cury ; but many thermometers for 



special uses are filled with colored 

 alcohol. The mercury or alcohol is contained in a 

 glass ball from one side of which arises a long and 

 thin hollow tube with a very small bor.-. and the ball 

 and tube are fastened upon a flat piece of metal or 

 wood upon which are marked various degrees. The 

 uniformity of the bore is tested by introducing a 

 small quantity of mercury and moving it along the 

 tube from end to end by air forced out of a small 

 india-rubber ball attached to one extremity. If the 

 column is observed to occupy the same space through- 

 out the bore is considered to hoof uniform diameter. 

 This process is called the calibration of the tulw. The 

 ball, or bulb, and part of the tube are filled with mer- 

 cury that ha-i be,. n strained through chamois leather. 

 In the usual process of filling thermometers a lamp is 

 held to the bulb until the air is highly rarefied ; tin- 

 end of the lulu: is then placed in a vessel of mercury, 

 the lamp remove, I. ami the mercury MM* in the tnl- 

 ty the i-ooliiig and condensing of the air in the bulb. 

 Ihc bulb is then held downward and the mercury 

 heated so that, in expanding, it entirely tills the tube. 

 Then the ton of the glans tuU- i- sealed with a blow- 

 pipe ; and tin: mercury, contracting as it cools, falls 

 down in the tul>e toward the bulb, leaving alxivc it a 

 vacuum. I'pon tin- application of heat to the bulb 

 the mercury expands and rises in the tube in pr,,por- 

 tion_; or it shrinks and drops in the tube as it cools, 

 s the bulb and the tuU- it is necessary to have 

 a graduated seal.- in order to make the instrument of 

 practical service. The three principal scales in use 

 are Fahrenheit '>. Reaumur's, an i tie 'Centigrade. The 

 cale used for ordinary puriMises. both in Kngland and 



bulb of the thermometer is placed in In.iling water, 

 and the height to which the mercury rises is marked 

 by a scratch on the tuU- : it is then put into melting 

 snow or ice, and another scratch is made at the point 

 where the mercury has dc.Mvndcd. The space be- 

 tween these two marks is divided into |sn equal parts. 

 Called decrees, and (hoe divi>ion> are eai lied upward 

 to nearly the end of tin; tu!>c. and downward toward 

 the bulb ; the upper scratch, indicating the heat of 

 boiling water, is marked llll'. and the lower one, the 

 free/ing point of water, is :;/ The zero point was 

 intended to mark the temperature of a mixture of 

 snow and suit, which was Mipp<c.l to be the utmost 

 possible natural cold. On toe scale of Reaumur's 

 thermometer the zero is at the five/ing point of water, 

 and the boiling point is marked MI. The (Yntu'rade. 

 differs from Reaumur's only in bavins: the space be- 

 tween the lulling and freezing point of water divided 

 into 100 parts instead of MI. The " renter ther- 

 mometer,' or "maximum and minimum thermom- 

 eter." has two bulbs, tubes, and scales on the same 

 instrument; one bulb is filled with mercury and the 

 other with colored spirit. In each tube a piece of 

 enamel, about half an inch long and fitting the cavity, 

 is introduced ; the one. in the mercury is to register 

 the highest, and that in the spirit to register the 

 lowot, degree of boat. They act in the following 

 manlier: The spirit, when rising in the tnlie. wets 

 the enamel and passes by it so that the elevation of 

 temperature does not affect its position, but when the 

 spirit sinks it carries the enamel with it, thus register- 

 ing the lowest temperature, so that the distance the 

 enamel is found down the tnl><> indicates how low the 

 spirit may have descended in any particular time, say 

 a night. Mercury, on the other hand, does not ad- 

 here to the enamel, and therefore, on rising, pushes it 

 up in the tube, but on descending leaves it behind, the 

 height at which the enamel is found up the tube in- 

 dicating the highest point to which the mercury had 

 risen, and consequently the highest temperature. To 

 adjust the instrument, a slight tap or shake will make 

 the index in the spirit-tube rise to the surface of the 

 spirit, where it is held by the adhesive quality of the 

 liquid, and by the same process that, in the mercurial 

 tube, will fall to the surface, but will nob penetrate 

 the mercury, owing to its great density. 



In making very accurate thermometers the boiling 

 point is found by immersing the instrument in - 



' in the water itself, as water really boils at 

 different temperatures depending upon various eireum- 

 sUinces. whilst the temperature of the steam is uni- 

 form. Even with the greatest care in constructing, the 

 indications of a thermometer are liable to derange- 

 ment ; and this result may come more particularly 

 from the bulb not resuming its former capacity after 

 being heated to a high temperature. Such a fault aa 

 this may not be discovered until comparison has been 

 made with thoroughly reliable thermometers. 



Aside from the thermometer certain appliances must 

 be used to assist in case of finding temperature in 

 inaccessible places, like the different depths of the 

 sea, etc. Siemens has invented a method of ascer- 

 taining, the temperature at such depths, depending on 

 the principle that the electric resistance of metals is in 

 proportion to the increase of their temperature. The 

 process requires two coils of the same kind of plati- 

 num wire which shall have equal resistance. Tim 

 cnd> of the wires are connected with long and thick 

 copper wires; so that, if necessary, the coils maybe 

 placed at a eon>idcrable distance from the galvanome- 

 ter. The copper terminals are adjusted so that each 

 coil shall have the same resistance ; but such resist- 

 ance should be small in comparison with the resistance 

 , of the coils themselves One of the coils is sunk to 

 the required depth in the si a. and the other is placed 



the United States, in Fahrenheit's, although both this in a jar of water on the deck of the ship. The tern- 

 and Reaumur's are sometimes marked on the same in- 1 pcraturc of the water in the jar is adjusted until the 



