620 Summary Vie*w of the Progress of Gardenings 



with a warm day when there is no breeze. The great import- 

 ance of this improvement has induced us to question every 

 person, that we have seen, who has visited Mr. Penn's establish- 

 ment at Lewisham during the last summer; and we have in- 

 variably found that they agree with us in our opinion of it ; and 

 one writer, a scientific gardener of great practical experience, 

 N- M. T., p. 640., is even more sanguine than either ourselves or 

 Mr. Willmot. The last gardener that we have seen who visited 

 Lewisham was Mr. Reith, head gardener to the viceroy of 

 Ireland. About the middle of October, he was in Mr. Penn's 

 orchidaceous house, when the temperature was at 80°, and 

 found it as agreeable as that of a green-house, or the room of a 

 dwelling-house, with the air at 60°. Mr. Reith is the reverse 

 of a theorist, and had only recently heard of Mr. Penn's im- 

 provement; he did not even know that there was any account of 

 it published in the Gardetier's Magazhie, and hence he could 

 have no previous prejudices respecting it. The articles on 

 atmospheric moisture, and heating by hot water, by Mr. Rogers, 

 deserve to be carefully studied by every person who has the 

 management of hot-houses, or is about to build or heat plant 

 structures. There appears to be no doubt of Mr. Shewen's 

 boiler being the best for garden purposes, on a moderate scale, 

 that has yet been brought into notice. 



Landscape-Gar dening. — The principal remarks on this sub- 

 ject will be found in our Notices of Country Seats and Gardens 

 (p. 49. 233. 329. and 569.) ; and it is, perhaps, in the form in 

 which we there introduce them, that they will be found of most 

 use to practical gardeners. In this way we intend to illustrate 

 one principle after another till we go through the whole science 

 of the art. We have, in the present volume, spoken for the 

 first time of the axis of symmetry (p. 233.), a most important 

 subject when rightly understood. The axis of symmetry is 

 founded on this principle: that all the most beautiful objects 

 or scenes in nature are symmetrical ; that every symmetrical 

 object forms a whole ; and that every whole consists of at least 

 three parts, a beginning, a middle, and an end ; or, in other 

 words, a centre and two sides. Now, in this centre, whether 

 visible, or supplied by the imagination, is the axis of symmetry. 

 In the simplest kind of symmetry, the two sides are equal and 

 alike, and the axis is, of course, easily discovered ; but in cul- 

 tivated and refined symmetry, the sides are unequal, and so 

 combined and varied with the centre, that it requires the eye 

 of a philosophical artist to detect the axis; which, in other 

 words, is called the axis of the composition. If it is once ad- 

 mitted that no scene can be truly beautiful or satisfactory that is 

 not more or less symmetrical, then we have only to search for 

 this quality in every building or landscape presented to us for 



