24 CARNEGIE INSTITUTION OF WASHINGTON. 



Many other researches in progress are described in the Director's current 

 report, to which reference must be made for further details; but two of 

 peculiar interest, in preparation for textual publication, may be cited, namely : 

 "Letters of Delegates to the Continental Congress relating to its transac- 

 tions"; and "The American proceedings and debates in Parliament." 



The principal steps which have been necessary and in large degree pre- 

 liminary in the development of the work of the Geophysical Laboratory are 

 recounted with instructiv particularity by the Director in 

 Th f9 eophysicaI ^is report for the current year. They are the steps re- 

 quired to pass from a merely descriptiv knowledge of rock 

 formation to a knowledge based on definit mesurements. Briefly stated, 

 these steps are four in number, namely: provision for correct temperature 

 determinations over the entire range involvd in the processes of rock forma- 

 tion; provision for like determinations of the chemical reactions of these 

 processes ; provision for precise microscopic, optical, and crystalografic mes- 

 urements ; and provision for the quantitativ applications of high pressures to 

 rock masses and rock constituents. 



In supplying the desiderata just indicated for its own special work, the 

 laboratory has alredy achievd results of prime importance also to many 

 other fields of physical and chemical science. Thus, two contributions of 

 great import to general physics and chemistry have been brought out during 

 the past year. The first of these is a determinate extension of the scale of 

 temperature mesures from about 300 C. to about 1600 C. This is a fitting 

 supplement to the classic work on thermometry begun more than thirty years 

 ago under the auspices of the International Bureau of Weights and Meas- 

 ures. It must take rank, in fact, with the fundamental advances in the tech- 

 nique of thermometry. The other contribution is a determination of the 

 system of compounds which may arise in combinations of the three most 

 important oxides entering into the composition of rocks, namely, silica, lime, 

 and alumina. This system is of special economic interest, since it includes, 

 among many other compounds, the hitherto much studied but baffling Port- 

 land cement. The complexity of the investigations requird to analyze this 

 system is indicated by the facts that it involvs the interaction of fourteen 

 minerals and the formation of sixteen ternary eutectics, or substances whose 

 melting-points are lower than those of the primary constituents. 



Many other important investigations are outlind in the Director's report 

 and the productivity of the laboratory may be inferd from his citation and 

 review of twenty-five publications emanating from the staff during the year. 

 It is of interest to note in this connection that researches from the labora- 

 tory find redy access for prompt publication thru current journals both at 

 home and abroad. Many of these papers have alredy been publisht in Ger- 

 man as well as in English and arrangements have been made during the year 

 to maintain this doubly effectiv mode of publication. 



