SECRETARY'S REPORT. 15 



the same way, they must protect the sources of our springs 

 and running streams, so that their destruction must increase 

 the liability to drought in the whole adjacent region. The 

 last effect has probably been produced in the manner indicated, 

 whatever may be our conclusion on the general question of cli- 

 mate ; and I think most men can call to mind streams which are 

 much smaller now than formerly, rivers that have dwindled 

 almost to brooks, brooks that have become little rills, and 

 rills that no longer exist. The same process is going on upon 

 the continent of Europe, and many of the large rivers there 

 have become perceptibly smaller, and probably from the same 

 causes, since it is pretty conclusively shown that the amount of 

 rain, so far from having diminished, has slightly increased since 

 the year 1689, when the positive data as to the quantity of 

 rain at Paris begin. The same slight increase has also proba- 

 bly taken place at Milan. Accurate observations were made 

 on the Oder from 1778 to 1835, and on the Elbe from 1728 

 to 1836, which establish a very considerable progressive dimi- 

 nution of water, and from which it appears that, if the diminu- 

 tion continues in the same ratio as since 1781, it will be 

 necessary, after 1860, to change the form of vessels used on 

 the Elbe, and to construct those of less draught. The de- 

 crease there is ascribed to the causes specified above, and 

 chiefly to the clearing up of forests, the draining of ponds and 

 marshes, and the reclaiming of swamps. 



We have seen that no accurate records were kept in the 

 early history of the colony ; indeed, that there were no means 

 of keeping any till the middle of the last century. The diaries, 

 both manuscript and published, which have been consulted, 

 give some information on this subject, though it is more gen- 

 eral and less to the point than could be desired. We learn 

 from them that there were many winters when it was common 

 to pass with men aud teams to and from the islands in Boston 

 Harbor, Shirley Point, and across the river to Charlestown. 

 We find, too, that not unfrequcntly the snows were very deep 

 and the roads impassable.. But all deductions from such vague 

 accounts as those are unreliable, when compared with those 

 drawn from careful registers of the weather. 



On the other hand, we may infer that our climate has not 



