[ 108 ] 16 



Institution, by Professor Arnold Guyot. The following are the contents of 

 this volume, viz : 



1. Thermometrical tables for the conversion of the scales of different 

 thermometers into each other. 



2. Hygrometrical tables giving the elastic force of vapor, the relative 

 humidity &c. 



3. Barometrical tables for the comparisons of different scales, reduction 

 of observations to the freezing point, and correction for capillary action. 



4. Hypsometrical tables for calculating altitudes by the barometer, and 

 by the difference of the boiling point. 



5. Tables of the corrections to be applied to the monthly means to obtain 

 the true mean. 



6. A set of miscellaneous tables frequently required in physical investiga- 

 tions. 



These tables Supply a desideratum in the English language, and will 

 doubtless be highly prized by all engaged in physical research. It is pro- 

 posed to extend their number so as to include a wider range of objects, and 

 to publish them in parts to suit different purposes. Copies will be dis- 

 tributed Vv'ith the quarto volumes of our publications, and sent to meteoro- 

 logical observers. The tables have been stereotyped and may therefore be 

 offered for sale at a low rate. 



Since the date of the last report, a number of separate memoirs have been 

 boimd together so as to form the second volume of the series of Smithsonian 

 Contributions. The memoirs, an account of which has just been given, 

 will be ready for distribution during 1852. 



The second volume has been forwarded to all the colleges and other 

 institutions specified in the rules adopted for the distribution of the Smith- 

 sonian publications in this country, and to all the first class libraries and 

 principal literary and scientific societies abroad. Through the liberality of 

 the members of the Senate of the United States and its officers, we have 

 been enabled to send to our foreign correspondents, in addition to our own 

 publications, copies of reports to Congress, and other works published at 

 the expense of ^government. In return, the Institution has received a series 

 of flattering acknowledgements and valuable presents, not only of the cur- 

 rent numbers of transactions, but in several instances, of entire sets of all 

 the volumes. 



The promotion of knowledge is much retarded by the difficulties ex- 

 perienced in the way of a free intercourse between scientific and literary 

 societies in different parts of the world. In carrying on the exchange of 

 the Smithsonian volumes, it was necessary to appoint a number of agents. 

 Some of these are American consuls, and other respectable individuals, who 

 have undertaken in most cases to transact the business free of all charge, 

 and in others for but little more than the actual expense incurred. These 

 agencies being established, other exchanges could be carried on through 

 them, and our means of conveyance, at the slight additional expense owing 

 to the small increase of weight ; and we have accordingly offered the 

 privilege of sending and receiving small packages through our agency to 

 institutions of learning, and in some cases to individuals \\'hio choose to avail 

 themselves of it. The offer has been accepted by a number of institutions, 

 and the result can not fail to prove highly beneficial, by promoting a more 

 ready communion between the literature and sfiiente of this country and 

 the world abroad. 



