AERATION OF VINERIES. 49 



called Panicum maximum — is well known. I have it from the 

 Isle of France and Martinique. It is said to be of African origin, 

 and is now, according to Humboldt, cultivated all over South 

 America for cattle. It is a species with a soft, succulent, nutri- 

 tious herbage, and therefore of great value. Its power of resist- 

 ing drought is a new fact, and is so well attested by the evidence 

 which Lord Grey has transmitted that I do not hesitate to advise 

 his Lordship to cause it to be introduced to Australia experimen- 

 tally. There is only one thing in that country which is likely to 

 interfere with the success of the trial, viz. the lower temperature 

 of the soil than in tropical America. But grasses have a great 

 aptitude for reconciling themselves to differences of climate ; and. 

 various species of Panicum, one of which is not very unlike the 

 Para grass, already inhabit the whole breadth of Australia. I 

 therefore regard tlie experiment as being eminently deserving his 

 Lordship's favourable consideration. 



I have, &c. 



John Lindley, 

 JJ. Halves, Esq., M.P. Vice-SecrcUry. 



VJI. — The Aeration of Vineries, as practised at Boivood, the 

 seat of the Marquis of Lansdowne, F.H.S. By John Spencer, 

 C.M'.U.S., Gardener tliere. 



(Conimuuicatcd Dec. 6, 1848 ) 



The imperfect matnier in which many of our forcing-houses are 

 ventilated is a constant cause of complaint amongst gardeners, 

 and various plans have of late been recommended to remedy the 

 evil and to dispense with the usual mode of letting down the roof- 

 sashes every time air is to be given. Having occasion during 

 the autumn of 1847 to replant an early vinery, I took the oppor- 

 tunity of arranging the aeration of it in accordance with the plan 

 which accompanies this paper, and it has so far answered my 

 expectations, tiiat I now venture to submit it to the Council of 

 the Horticultural Society, as a means whereby structures of this 

 description maybe efficiently aerated at all times and at a trifling 

 expense. 



By a reference to the plan it will be seen that the house in 

 question is one of the common lean-to description, and was 

 placed against a wall previously erected, which will account for 

 its unnecessary thickness. The chamber containing the heating 

 apparatus runs the length of the house (see /'), and into this 



VOL. IV. E 



