BAROMETERS, WATER. 



51 



mentation Fund). Statements were made to 

 the effect that the last year's accounts of the 

 churches showed an increase of 5,300 mem- 

 bers, 30,548 scholars, and 3,427 teachers. A 

 scheme for the constitution of the Union was 

 presented, and laid over to be discussed at the 

 meeting of the body in the spring of 1881. 



The receipts of the Baptist Missionary So- 

 ciety during the year ending March 31, 1880, 

 for general purposes, amounted to 45,233, 

 and, including contributions for special funds, 

 to 50,351. The amount of general income 

 was ths largest ever received in one year, ex- 

 cept in the Jubilee year of the Society. The 

 condition of the missions in India, Ceylon, 

 China, Japan, West Africa, Central Africa 

 (Congo), the Bahamas, San Domingo, Trini- 

 dad, Jamaica, Norway, Brittany, and Italy, is 

 reviewed in the report of the Society. In all, 

 so far as was reported, the missions included 

 82 missionaries, 309 other laborers, 407 sta- 

 tions, 33,805 members, 5,141 day-scholars, 166 

 teachers, and 4,346 scholars in Sunday-schools. 

 The income of the Zenana Mission amounted 

 to 3,658. Twenty-seven ladies and forty-six 

 native teachers were employed in connection 

 with the mission, about 700 children were in- 

 structed in the Zenanas, and 1,100 woman lis- 

 tened to the reading of the Bible. A Home for 

 the Ladies in Dalhi was ready to be occupied, 

 and 2,300 had been promised toward the 

 erection of a home in Calcutta. 



V. GENERAL BAPTISTS. The General Bap- 

 tist Conference met at Nottingham, England, 

 June 22d. The Rev. James Maden, of Mac- 

 clesfield, presided. The Secretary reported an 

 increase of 452 members, making the whole 

 number of members in the home churches 24,- 

 455, and, including the mission churches of 

 Orissa, 25,449. Petitions to the House of Com- 

 mons were adopted in favor of the closing of 

 the public-houses on Sunday, and of the abro- 

 gation of the enactments by which the opium- 

 trade between England and China is made 

 lawful. A resolution was adopted approving 

 of the recognition and application by the Prime 

 Minister of the principle that no religious 

 views which a man might have should dis- 

 qualify him from holding high office under the 

 Crown. 



The receipts of the General Baptist Foreign 

 Missionary Society for the year ending in May, 

 1880, were 8,727, and its expenditures 8,- 

 538. Fourteen English missionaries were em- 

 ployed in India, and another missionary had 

 been accepted for service in the same field. 



BAROMETERS, WATER. The specific 

 weight of mercury being 13-596, a hydraulic 

 barometer in which a column of water about 

 10 metres high counterbalances the mean press- 

 ure of the atmosphere, instead of the mercurial 

 column of 76 centimetres, shows much finer 

 variations of pressure than the ordinary ba- 

 rometer. The simple contrivance of Babinet, 

 consisting of a long, thin tube of glass inserted 

 in the neck of a tightly closed bottle, in which 



the water had been forced up the tube, enabled 

 him to observe the minute variations of atmos- 

 pheric pressure during a small space of time; 

 but the observations were vitiated by the effect 

 of variations of temperature in vaporizing the 

 water and dilating or contracting the mass of 

 the water and the air. Another French ph} r s- 

 icist has constructed a permanent water ba- 

 rometer in which all the inequalities caused by 

 temperature are avoided or compensated, and 

 which is, therefore, as precise as it is sensitive. 

 A reservoir of air is sunk in the floor of a closed 

 cellar, in which the temperature is practically 

 the same at all times of the year. In the reser- 

 voir is placed a large demijohn, in which a tube 

 is inserted, which is carried up to the chamber 

 in the floor of the building where it is desired 

 .to observe the barometric variations. The ca- 

 pacity of the reservoir can be from one to 100 

 litres or more, and can serve for a number of 

 different barometers if desirable. In the In- 

 stitute there are three connected with the same 

 vessel of water, of a capacity of 85 litres. The 

 copper pipe which connects with the glass tube, 

 on which the rise and fall of the column of water 

 is indicated by a scale, can be carried up from 

 the demijohn at any inclination. The glass in- 

 dicator need be no more than a metre in length 

 to allow for the height of the vessel in which 

 the tube terminates, and show the extreme va- 

 riations of barometrical pressure, which fall 

 within 70 centimetres of the scale. The ba- 

 rometer of the Societe^ de 1'Encouragement has 

 a copper tube 16 metres long with an interior 

 diameter of 3 millimetres ending in a glass tube 

 with 8 millimetres' interior diameter. Just 13 

 millimetres on the scale correspond to the mil- 

 limetre divisions on the scale of the quicksilver 

 barometer, the deviation from the exact ratio 

 of 13-596 between the specific weights of quick- 

 silver and water representing the allowance to 

 be made for the sinking of the level of the water 

 in the reservoir answering to the rise of the 

 column in the tube and that due to the com- 

 pression of the air in the reservoir, and also to 

 the increase in the specific gravity of the water 

 by the admixture of glycerine, or sometimes 

 sulphuric acid, which is necessary to keep the 

 water in the pipe from freezing if it is exposed 

 to frost. In the building of the Societe de 1'En- 

 couragement no preventive against freezing is 

 needed, but a tincture of f uchsine in the water 

 reduces the height of the column about one mil- 

 limetre. The water is forced up the pipe by suc- 

 cessive blasts through a tube inserted in the 

 cork of the demijohn, which dislodge portions 

 of the air in the tube, the globules of air driven 

 out through the mor.th of the pipe making 

 way for the ascending column of water which 

 is held up by the pressure of the atmosphere. 

 When the summit of the column has nearly 

 reached the point on the scale corresponding 

 to the reading of a good mercurial barometer, 

 it is brought into exact agreement by pouring 

 into the vessel a sufficient quantity of water, 

 or taking water out if the level of the column 



