502 PROTECTION AGAINST FROST. 



Sal (Shorea rcbusta) and other winter-green and ever green 

 trees.* Very extensive damage was done to saplings and 

 poles in N.-W. India by severe frost in February, 1905. 



4. Register of Severe Frosts. 



Damage by frost is usually local. There are, however, 

 years in which damage is done over extensive areas, these 

 years being termed frost-years. The dates below refer solely 

 to frost-years. 



In Central Europe, during the fifty-two years from 1848 to 

 1899, severe late frosts occurred, on the average, every other 

 year ; the worst years for persistence and severity of these 

 frosts being 1854, 1866, 1876, 1878, 1880 and 1894. Not a 

 single month is absolutely free from frost, not even July or 

 August. On May 21st, 1894, the foliage of the oak standards 

 in the lower ground of Prince's Coverts, near Esher, in Surrey, 

 was entirely destroyed by frost, whilst much damage was also 

 done to the ash and other underwood ; the crowns of the oak 

 trees, which were blackened by the frost, did not become 

 completely green again till the middle of July. A similar 

 event happened in the Forest of Dean on May 29th, 1819.1 



In Central Europe, during the present century, there has 

 been one hard winter every five or six years, the coldest years 

 previous to 1895 being 1829-30 and 1879-80, when atGiessen, 

 on the 10th December, 1879, and in February, 1830, tempera- 

 tures of 81 and 25 below zero, F., were observed. The lowest 

 temperatures measured at Coopers Hill were 16 F., in 

 December, 1879, and 10'l, in February, 1895. Lough- 

 borough is one of the coldest places in Britain, and its minima 

 on the 8th, 9th, and 10th February, 1895, were 5, 4 and 1 

 below zero, F. During 1895, the frost continued night and 

 day at Coopers Hill from January 25th to February 18th, 

 and skating lasted till the middle of March. 



5. Protective Measures. 



Protective measures against frost may be taken during the 

 formation and utilisation of woods. 



* Many trees in India lose their leaves in tin- spring after retaining them 

 throughout the winter. 



t "The Forest of Dean," by II. (J. Nicholls. J. Murray, London. IS'iS. 



