PREFACE 



TO THE FIRST EDITION, 



To PROF. JOSEPH HENRY, 



Secretary of the Smithsonian Institution. 



Sir,— 

 In compliance with your instractions, I have prepared the collection of 

 Meteorological Tables contained in the following pages. I have en- 

 deavored to render it useful, not only to the observers engaged in the sys- 

 tem of Meteorological Observations now in operation under the direction 

 of the Smithsonian Institution, for whom it was immediately designed, but 

 also to any Meteorologist who may desire to compare and to work out 

 portions of the vast amount of Meteorological Observations already ac- 

 cumulated in the stores of science. 



The reduction of the observations and the extensive comparisons, with- 

 out which Meteorology can do but little, require an amount of mechanical 

 labor which renders it impossible for most observers to deduce tor them- 

 selves the results of their own observations. The difficulty is still further 

 increased by the diversity of the thermometrical and barometrical scales 

 which Meteorologists, faithful to old habits rather than to science and to 

 reason, choose to retain, notwithstanding the additional labor they thus 

 gratuitously assume to themselves. To relieve the Meteorologist of a 

 great portion of this labor, by means of tables sufficiently extensive to 

 render calculations and even interpolations unnecessary, is to save his 

 time and his forces in favor of science itself, and thus materially contribute 

 to its advancement. But most of the tables useful in Meteorology being 

 scattered through many volumes, which are often not of easy access, this 

 collection will be, it is hoped, acceptable to the friends of Meteorology, 

 and will supply a want very much felt in this department of the physical 

 sciences. 



