1 86 CARNEGIE INSTITUTION 



Laboratory construction is a matter of extreme importance and 

 one which has been, relatively speaking, neglected. Vast ingenuity 

 has been applied to the perfection of apparatus, while little pains 

 has been taken to provide for that freedom from mechanical and 

 thermal disturbance without which many instruments of precision 

 cannot possibly give the best results of which the}' are capable. 

 Hence also the work done in an ill constructed laboratory, other 

 things being equal, w^ll be inferior in quantity and quality as com- 

 pared with that achieved in a suitable building. 



Institutions Visited. 



In accordance with the plans thus laid, I visited the Cavendish 

 laborator}' at Cambridge, the laboratory of the Sorbonne and the 

 astronomical observatory at Paris, the laboratory of the Bureau In- 

 ternational des Poids et Mesures at Sevres, the physical laboratories 

 of the universities of Strasburg and Wiirzburg, the geophysical 

 laboratory' of Gottingen, the laboratories of the Physikalisch-Tech- 

 nische Reichsanstalt of Charlottenburg, the laboratorj- of the Normal 

 Aichungs Komission of the same place, the Astrophi'sical obser\'atory 

 of Potsdam, the physical laboratory of the University of Leipzig, the 

 cryogenic laboratory, and the Astronomical observatory of Leiden. 



So far as possible, I consulted the chief physicists or astronomers 

 of these institutions on the main points of my inquiry. Professor 

 J. J. Thomson was absent and Professor Onnes, of the cryogenic 

 laboratory, was engaged on the day of my visit. On the other 

 hand, I had instructive interviews with Professor George H. Darvvin, 

 Professor Charles Chree, Sir Archibald Geikie, Professor E. Suess, 

 and others. 



Nearly everywhere I have found physicists dissatisfied with the 

 construction of their laboratories and fully persuaded that radical 

 improvements are possible. Satisfactorily firm piers have been con- 

 structed only at Potsdam and Leiden, and in both these places the 

 successful result seems due rather to natural conditions than to 

 peculiarities of construction. Fairly uniform temperatures, except- 

 ing in underground chambers, have not been attained, although a 

 majority of physicists are of opinion that they might be brought 

 about. Heating and ventilation are usually' no better than in any 

 ordinary office building. 



An ideal laboratory' would be free from magnetic, electrical, or 

 mechanical disturbances and from unintentional changes of temper- 



