NOTES ON THE PROLONGED FROST, 1890-gi. 



65 



fall of snow from Deoembev lOth to Januaiy Kjlh inclusive correspondecl to -81 in. 

 of rain. 



During the whole period there was fortunately but little wind. A force of '3" 

 was the maximum registered, and that on one occasion only, and most of the time 

 easterly winds ])revailed. 



ClI.\RT SHOWING MkaX TeMTERATURF. AND MiXI.MUM TEMPERATURE EACH DaY DURING 



Prolonged Frost of Winter of 1890-91. 



Tkici (upper) line Mean Temperature for day : thin (lower) line Minimum Temperature 



for day. 



As for some weeks there was only a thin covering of snow on the ground, the 

 effect of the continued cold will probably have proved very disastrotis to vegetation 

 Some of our members who are interested in agriculture will probably have some- 

 thing to say on this point. 



The effect of the prolonged frost on water mains : — No observations were taken 

 of the earth temperature at varying depths, though such a series would be very 

 interesting. What that temperature was, however, can be judged from its effect 

 upon the Chelmsford water mains. 



The water in the more superficial mains was frozen before Christmas, and 

 before the break up of the frost the mains at a depth of two feet had become 

 affected. This of course caused great inconvenience in many parts of the town, 

 and it was sometime after the thaw had set in that the ice in such mains melt:d. 

 When this occurred the havoc wrought by the expansion of the water in the 

 art of freezing became apparent. The mains had been fractured in most diverse 

 ways and to varying extents and water w'as rushing to waste at numbers of 

 places. 



The moral of this experience is that water mains should be laid at a greater 

 depth than is frequently the case. The slight additional first cost of adopting 

 such a course is as nothing compared with the great inconvenience, annoyance 

 and damage wrought by a single severe frost when the pipes are too superficially 

 bedded. 



F 



