J'OND f'lTT/ntRl.!. r-ry 



[127] 



llMVv.ill float abouf under ll.o ice in :, ,h,/.<.(| vnuihium -.uui (inallv 

 liv(;u(<) th.' ice will, lliei. lins. Delius is of opinion tlii.l tin- l„-k of 

 <.x.V4:e" ciHinol cause tliis <-on(li(ion, hut ti.ai i( is rather ..ccasiond l.v 

 iui accuniulalion of gases Iron, ll.e nuul at tl.c bottom wliicl. ,ann.it 

 escape thro.igh the ice, and wJiic^i will be particularly strong i,, shall.)\v 

 water. While Von Beider con.^iders air-boles unnecessary only in those 

 l)()n(ls which have a constant supply of fresh water, Delius thinks they 

 are not needed even in ponds wbich have no such supply, Init Mliic'h 

 are of sufficient depth. 



1 am inclined to share these views, ail (he more as 1 have found them 

 correct as regards sky ponds, but I have for my own part never omitted 

 to make air-holes, and would not r(M-ommend any one to omit it merely 

 for the purpose of ascertaining whether airholes are n<'cessary or not. 

 The majority of i)ond cultivators, both in former and more recent times, 

 consider air-holes necessary, at any i-ate in scNcre winters, and it will 

 under all circumstances be better to be too careful than to exercise too 

 little care. I consider it, howevei', injurious to nmke air-holes right over 

 the place where the tish congregate, or in its immediate neighborlM.od, 

 astherel)y they are(h-i)rived of the protection against cold which the 

 cover of ice affords them. In small ponds of suflicient depth, and with 

 a conrtnuous How of water, the air-holes may be dispensed with, but the 

 breaking of the ice near tlu^ places where the water flows in and out 

 should in no case be omitte<l. In largr ponds, where the water flows in 

 :it a considerable distance from the i)Iace wheie it leaves the jmnd, and 

 where the current is not very strong, air-holes become an absolute ne- 

 cessity, and this is probably the i-eason that on the Wittingan j.ond farm, 

 which possesses many ponds of great si/e, gi-e:it stress is laid on sup' 

 plying a large nund)er of«ir-holes. 



Considering the great imjiortance of this question, it juay l)e desira- 

 ble and proper to quote some other practical i>on<l cultivators. Tschei- 

 ner says: "In winter, wIhmi (he jxmd is coveicd with a thick coat- 

 ing of ice, it is necessary to make holes in the ice in several ]>laees, so 

 as to give the fish some fresh air ; and to prevent tln-se holes from freez- 

 1 iiig two sticks are stuck in them crosswise, iind on these is placed some 

 I straw or brush-wood. The snow which falls on (his covering of ice is 

 ; probably more helpful than hurtful, because it lessens the cold, and 

 I thereby prevents the ice from becoming too thick. On the other hand, 

 I it produces darkness in the ponds, which may prove dangerous to the 

 I fish. Around the air-holes, therefore, the snow should alwavs l)e swept 

 j away.i-" * 



' Reimann says: "The less water flows into the ]Mm<l the jnore and 

 I greater air-holes must be made in the ice. The same applies to large 

 I ponds, even if they should have a constant stipply of water. The more 

 ^ water flows into a moderate sized pond, tlie less in munberand smaller 

 m size need the air-holes be. Ponds whose water supply is scant must 



* Tscheiner, p. 193. 

 H. Mis. as 3S 



