IX. 



The Tornado of August 22d, 1851, in IValtham, West Cambridge, and Medford, Mid- 

 dlesex County, Mass. (If 1th a 3Iap.) 



By henry L. EUSTIS, A. M. 



{Communicated February 3d, 1852.) 



Meteorology is every day gaining a stronger foothold, and taking a higher rank 

 among the sciences of modern times. It would be no great tax upon our powers of 

 retrospection, to look back to the period when its deductions were regarded, by most 

 persons, as the mere speculations of scientific enthusiasts, having no tests whereby their 

 fallacy or accuracy could be demonstrated, and therefore possessing little practical value. 

 Nor is this to be wondered at, since it is preeminently a science whose laws can be 

 deduced only from long-multiplied observations, affording a connected series of facts, 

 which, however diversified by temporary or local circumstances, may still betray, amid 

 all their variety, an obedience to certain fixed principles. How far man can go in his 

 attempt to elevate it into an exact science, whose deductions shall be worthy of implicit 

 confidence, is not for me to say. But thus much may be confidently asserted : that, as a 

 means to this end, we need, not much speculation and theorizing upon a few facts, but 

 abundant observations, whereby theories may be tested, and their true value assigned to 

 them, in proportion as they accord with the facts observed, and may serve to explain and 

 account for them. 



Among the subjects which come within the proper domain of Meteorology, the laws 

 of storms hold no insignificant place. Accordingly, we have already a multitude of 

 theories upon the subject, each warmly supported and defended by its advocates, but of 

 which it is enough to say, that there is such a decided conflict between them, that they 



VOL. V. NEW SERIES. 24 



