MICROTASIMETER. 



MINNESOTA. 



5G3 



taining iron in a fine state of division. Pine char- 

 coal treated in this manner (although a non-conduct- 

 or aa a simple charcoal) has high conductive powers, 

 due to the iron ; and, from the minute division of the 

 iron in the pores, it is a most excellent material for 

 the purpose. 



All the substances named above are to be 

 inclosed in glass tubes or boxes provided with 

 wires to enable them to be easily inserted into 

 a circuit. 



But the form of microphone ultimately 

 adopted by Professor Hughes consists of a loz- 

 enge-shaped piece of gas-carbon one inch long, 

 a quarter of an inch wide at its center, and 

 an eighth of an inch thick. The lower point- 

 ed end pivots on a similar block ; the upper 

 rounded end plays free in another carbon block. 

 All of these pieces of carbon are impregnated 

 with mercury. This instrument is capable of 

 detecting very faint sounds made in its pres- 

 ence. If a pin, for instance, be laid upon or 

 taken off a table, a distinct sound is emitted ; 

 or, if a fly be confined under a glass shade, it 

 can be heard walking with a peculiar tramp 

 of its own. 



MICROTASIMETER. The microtasimeter, 

 one of Edison's many inventions, is a measure 

 of infinitesimal pressure, and incidentally a 

 measure of infinitesimal variations in bodies, 

 caused by changes of temperature, moisture, 

 etc. ; thus it is at once an exceedingly sensi- 

 tive thermometer, barometer, and hygrome- 

 ter. This instrument was employed very suc- 

 cessfully during the recent solar eclipse in 

 measuring the heat given out by the sun's co- 

 rona. The modus operandi of the microtasim- 

 eter as a measurer of temperature-changes will 

 be understood from the following description 

 of the instrument by Professor Prescott : The 



change of temperature causes expansion (or con- 

 traction) of a rod of vulcanite, which changes 

 the resistance of an electric circuit by varying 

 the pressure it exerts upon a carbon button 

 included in the circuit. The substance whose 



expansion (or contraction) is to be measured 

 is shown at A in the figure. It is firmly 

 clamped at B, its lower end fitting into a slot 

 in the metal plate M, which rests upon the car- 

 bon button. The latter is in an electric circuit 

 which includes also a delicate galvanometer. 

 Any variation in the length of the rod changes 

 the pressure upon the carbon, and alters the 

 resistance of the circuit. This causes a deflec- 

 tion of the galvanometer needle a movement 

 in one direction denoting expansion of A, an 

 opposite motion contraction. In order to as- 

 certain the exact amount of expansion in deci- 

 mals of an inch, the screw S is turned until the 

 deflection previously caused by the change of 

 temperature is reproduced. The screw works 

 a second screw, causing the rod to ascend or 

 descend, and the exact distance through which 

 the rod moves is indicated by the needle N on 

 the dial. When the microtasimeter is to be 

 used for measuring atmospheric humidity, the 

 strip of vulcanite is superseded by one of gela- 

 tine, which changes its volume by absorbing 

 moisture. 



MINNESOTA. The total receipts into the 

 State 'Treasury during the year ending Novem- 

 ber 30, 1878, including a balance of $133,271 

 on hand at the beginning of the year, were 

 $1,610,909. The disbursements amounted to 

 $1,562,410. The balance in the Treasury at 

 the end of the year was $48,499, which was 

 set down to the credit of the funds. The most 

 important sources of income were the follow- 

 ing: State taxes, $478,272; taxes from rail- 

 road, insurance, and telegraph companies, $189,- 

 552 ; county indebtedness to Reform School, 

 $14,313 ; sale of sinking fund bonds, $42,085 ; 

 sale of pine on school lands, $15,408 ; redemp- 

 tion of 15 Missouri bonds, school fund, $15,000 ; 

 sale of school lands, 1878, $69,667 ; collec- 

 tions on former sales of school lands, $63,- 

 086 ; sale of internal improvement lands, 

 1878, $45,467; collections, principal and in- 

 terest, on former sales of agricultural col- 

 lege lands, $14,560 ; interest on school-land 

 sales, $22,827; interest on permanent school 

 fund, $86,437; interest on lands sold and 

 collected on former sales, $20,722; State 

 loans, 1878, $200,000 ; school text-book 

 fund, paid by counties for books furnished 

 by contractor, $25,525. The chief items of 

 expenditure were : Legislative, executive, 

 fmd judicial expenses, $178,543; printing, 

 printing laws in newspapers, paper and 

 stationery, $50,853 ; for support of insane 

 hospital, reform school, deaf and dumb 

 and blind institution, soldiers' orphans, 

 normal schools, university, and State pris- 

 on, $312,813 ; public buildings and repairs 

 on Capitol, $38,022; prison work-shops, 

 etc., $25,634; interest on State debt, 

 $29,750; apportioned school fund, $217,241; 

 purchase of bonds for invested funds, pre- 

 miums, interest, and expenses on purchases, 

 $397,993; seed-grain, coal-tar, and iron for 

 grasshopper sufferers, $209,213; school text- 



