16 



REPORT AND OBSERTATIONS ON 



was constantly tied down so as to prevent its rising above 

 the top of the cylinder — and partially so during 1845. 

 These observations therefore are free from objection on 

 account of the additional surface exposed by the rod, though 

 there may have been some loss from evaporation. 



In taking the rain-gauge observations in the Longden- 

 dale district, the index rod was tied down from their com- 

 mencement in November 1846 to Midsummer 1847, since 

 which time the rod has been detached, and inserted only at 

 the time an observation is being taken. 



The streams were measured, one (the river Etherow) 

 three times a day, some twice a day, and others once a day. 

 But in the results, which are given in monthly amounts, it 

 has been found necessary to omit many months, in conse- 

 quence of the gauges being frequently injured and rendered 

 unfit for use for some days,' by the effects of violent and 

 destructive floods. 



