ACTA SOCIETATIS SCIEKTIARUM FEKNICJE. 



TOM. XX. JV» 3. 



ON 



NIGHT FROSTS 



AND 



THE MEANS ÜF PREVENTING THEIR RA\ AGES 



BY 



SELIM LEMSTRÖM. 



Wïth 4 plates and a map. 



•a< g> ' y ^ » C '- 



