Its ‘acuminated apex’, as Loudon called it, would not collect condensation and the ‘spread out’ base would provide a special place for small plants close to the glass. Loudon’s proposal had practical application because many of the desired species, particularly the palms, which were beginning to arrive from the New World grew to great heights. Loudon was obviously impressed by Mackenzie’s curved iron design; ‘ Its appearance is most elegant, and it admits of a happy combination of lightness with strength in the construction; it may be considered, with the improvements of which it is susceptible, as a most valuable acquisition to the horticultural architecture of this country.’ He had earlier suggested that iron could not be adopted for a forcing-house without considerable disadvantages and could only be used in houses for maturing fruits. However ,in a short time he became an avid proponent of iron construction and in 1816 he invented a wrought-iron bar that could be heated and then drawn through a special paper and even corrugated iron to demonstrate the potential for covered markets, schools, theatres and churches. He said that his new glass and iron buildings could be designed in almost any shape with ‘every conceivable variety of glass surface, without in the least interfering with the objects of culture’.
ALTHOUGH not an adept businessman, Loudon had a flair for writing and salesmanship. In his Remarks on the Construction of Hot-House, he compared the prices of various materials and thought his iron construction was better than ever’ the best constructed wood houses as Kew, Kensington Gardens, and Chiswick’. His most convincing argument was his bar graph comparing the amount of light blocked by wood and by iron-framed glasshouses. He said the dark area represented the lack of light and therefore ‘insipidity and tartness’, while the white was equated with ‘aroma and flavours’. Could any gardener or green-thumbed patron have resisted this graphic argument?LOUDON refuted major objections to iron, such as claims that the expansion and contraction of the metal causes glass to break, that iron loses heat by conduction, that it rusts and that it attracts electricity (lightning). He answered that most expansion and contraction occurred with brass and copper, not iron; that the house could be covered with canvas to prevent heat loss and that the bars could be lined with wood for insulation. To prevent rust the bars should be heated red-hot, then coated with coal tar or paint: tin, lead or pewter. As to lightning, he observed that even foundries, built completely of iron, had existed for fifteen years without any electrical damage. Loudon’s arguments had to be decisive because, at that time, the new iron glazing bars were much more expensive than wood.He envisaged a new style of architecture that ‘may be beautiful without exhibiting any of the orders of Grecian or of Gothic’ design.

被LOUDON称作的“尖顶”，不会聚集水汽，并且向外延展的底部
能够为靠近玻璃的小型植物提供一个特殊的空间。LOUDON的这个
提议十分实用。因为，许多众人渴求的植物，特别是刚刚从新世
界引进的棕榈树长得特别高大。LOUDON 很明显是被MACKENZIE的
曲型铁架设计所打动了，"它的外形极为优雅，并体现了建筑中轻盈
稳固的完美结合。可以认为，经改进之后的它，会被众人称为是
今天全国园艺建筑中极其宝贵的成就。以前，他建议，在温室建
造中使用铁会带来极大的不利因素，而且铁只可用在栽培果树的
暖房中。可是，在短时间内，他却成了热情的铁质建筑的倡导者.1816年，他发明了熟铁钢筋，这种东西经过加热以后，可以从一
种特殊的纸甚至是波状钢中穿过去。这充分显示了它在采用扣棚
建造方式的市场、学校、剧院和教堂方面的潜能。他说，他可以
把他的玻璃和铁构建的房子设计成“任何一个可以想像得到的任
意一种玻璃表面形态的形状，而且一点都不会影响到人文感观。
虽说不是一个精明老练的商人，但LOUDON 却具有写作和推销的天
赋。在温室建筑的注释中，他对比了不同材料的价格，并且认为
，他的铁质建筑比有史以来“建设最好的木质房屋，像Kew,
Kensington Gardens, and Chiswick’还要好。他最能使人信服
的论据就是他的横椽布局图，图中清楚地对比了在木质温室中，
木材所遮挡光线的多少和铁质温室中铁框所遮挡光线的多少。
他说“黑色区域代表着没有光线照射，所以就生长'平淡无味和酸
的'而白的区域就等同于生长出'芳香和可口的',能有任何园艺家
或栽培资助者来驳斥我的这个图解式的论证吗？LOUDON 反驳了一
些反对铁材的说法，像金属的膨胀与收缩会造成玻璃的破裂。铁
会把室内的热量传导出去，而且还会生锈和导致雷击。他回答道
，黄铜和铜所发生的膨胀和收缩是最大的，而铁却不是。可以用
帆布遮盖房子，防止热量散失,横椽之间可以用木头隔开，以
此绝缘。为防止生锈，可以把铁筋烧红，然后涂上煤焦油或油漆
：锡，铅或白蜡。至于雷击，他观察到甚至是一些完全由铁建造
的铸造厂，已经存在了15年，也没有遭受到任何雷击的损失。
LOUDON 的观点必须是毫无异议的，因为，在当时这种新型的铁质
玻璃隔栅比木头要贵得多。他构想了一个新的建筑风格，那就是
’不展示任何希腊或哥特式的设计规范，会是另一种美。