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POPULAR SCIENCE MONTHLY. 



tific and executive qualifications shall 

 be found. 



Section 3. — That the Secretary of the 

 Navy may detail for duty as astron- 

 omers at the National Observatory such 

 professors of mathematics and other of- 

 ficers of the Navy as he shall deem nec- 

 essary in the interests of the public ser- 

 vice; but on and after the passage of 

 this act no appointments shall be made 

 of such professors unless required for 

 service at the Naval Academy. 



Section 4. — That there shall be a 

 Board of Visitors of the National Ob- 

 servatory, to consist of one Senator, 

 one member of the House of Represent- 

 atives, and three astronomers of emi- 

 nence, to be selected by the Secretary 

 of the Navy. The Board of Visitors 

 shall make an annual visitation, or 

 more frequent visitations, of the Observ- 

 atory, advise with the director thereof 

 as to the scientific work to be prose- 

 cuted, and report to the Secretary of the 

 Navy on the work and needs of the ob- 

 servatory on or before the first day of 

 November in- each- year. The members 

 of the said board may receive an allow- 

 ance not exceeding ten dollars per day 

 each during their actual presence in 

 the city of Washington while en- 

 gaged on the duty of the board, and 

 their necessary traveling expenses; but 

 no officer of the Government appointed 

 on the board shall receive any addition- 

 al compensation for such duty above 

 his actual expenses. 



The probability that a National 

 Standardizing Bureau will be authorized 

 by the present Congress adds interest to 

 the plans of the National Physical Lab- 

 oratory recently established in Great 

 Britain. Experimental work, somewhat 

 limited in character, has for a long 

 while been carried on at Kew Observa- 

 tory, and it was hoped that the new lab- 

 oratories might be erected near by. 

 Plans were drawn up for a physical 

 building to cost $30,000, and an engi- 

 neering building to cost $20,000. There 

 was, however, opposition to the erection 

 of these buildings in the Old Deer 

 Park, and in October the Government 

 decided to assign to the laboratory 

 Bushey House and the surrounding 

 grounds, 25 acres in extent. The build- 

 ing as it now stands will be turned into 

 a laboratory for the more delicate meas- 

 urements, and a new laboratory for en- 



gineering will be erected. The work 

 that it is proposed to carry out, as soon 

 as the buildings can be occupied, in- 

 cludes the connection between the mag- 

 netic quality and the physical, chem- 

 ical and electrical properties of iron and 

 of its alloys, the testing of steam 

 gauges and various kinds of springs, 

 standard screws and electrical meas- 

 uring instruments, and optic and ther- 

 mometric determinations. These sub- 

 jects have an evident connection with 

 trade and industry, and there is every 

 reason to suppose that the cost of the 

 laboratory will be saved many fold every 

 year by economies in the arts and manu- 

 factures, while at the same time phys- 

 ical measurements can be carried out 

 in an institution of this character which 

 no university would be likely to under- 

 take. It should be noted that the Na- 

 tional Physical Laboratory is under the 

 direct control of the Royal Society, 

 which insures the highest attainable de- 

 gree of efficiency. 



A valuable contribution to the 

 study of the inert gases of the atmos- 

 phere is made by Professors Liveing and 

 Dewar in a paper read before the Royal 

 Society on December 13. The gases were 

 obtained by liquefying air by contact 

 with the walls of a vessel at atmos- 

 pheric pressure cooled below 7 200° C. 

 Some 200 ccm. of liquid air were thus 

 condensed, and the more volatile por- 

 tion was then distilled over into a re- 

 ceiver cooled with liquid hydrogen. This 

 portion, consisting of about 10 ccm. was 

 then passed into spectrum tubes, first, 

 however, traversing a U-tube immersed 

 also in liquid hydrogen. In this man- 

 ner the gas was completely freed from 

 every trace of nitrogen, argon and 

 compounds of carbon. The tubes showed 

 the spectra of hydrogen, helium and 

 neon with great brilliancy, but also a 

 large number of lines which could not 

 be referred to any known origin. This 

 shows conclusively that a sensible pro- 

 portion of hydrogen exists in the earth's 

 atmosphere, a point which has been 

 much disputed in the past. If it be true, 



