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to 



The Weekly Florists^ Review* 



Apbil 28, 1910. 



INSIDE-GLAZED GREENHOUSES. 



Dnring the last few years the Koyal 

 Botanical Garden in Berlin, Grermany, 

 has been moved to a less crowded and 

 more rural region, in the royal park, 

 Dahlem, near Steglitz, a suburb of Ber- 

 lin. The new buildings erected there to 

 accommodate the exotic plants are inter- 

 esting structures in several respects, but 

 chiefly because inside glazing has been 

 employed, to protect the steel frame- 

 work. Most prominent among them is a 

 very large steel-arch house for tropical 

 plants, though some of the smaller build- 

 ings also are notable. 



Inside glazing was adopted for those 

 greenhouses in which fairly high tempera- 

 ture and moist atmosphere would prevail. 

 Its purpose is not only to reduce the at- 

 tack of rust, but also to make it possible 

 to do successful repainting, inspection, 

 etc., without interfering with the plants 

 inside. It was desired also to get a 

 maximum amount of sunlight, uniformly 

 distributed, which is better attained with 

 framing- outside, because the shadows 



the framing of the large house will be 

 quite evident from the sectional drawing 

 reproduced herewith. The main arches, 

 spanning about 100 feet, with a rise of 

 seventy- seven feet, are three-hinged, of 

 such outline, however, as to give sub- 

 stantially vertical sides for a consider- 

 able height, therefore also affording 

 good headroom over the whole floor area. 

 The ends of the house are hipped to half- 

 hexagonal ground plan of the same pro- 

 file as the sides, instead of having ver- 

 tical gable walls. 



The arch trusses are spaced about 

 twenty and one-half feet apart. The 

 main purlins are two-plane lattice girders 

 (of triangular section), spaced twenty- 

 three feet apart, making a total of four 

 purlins on each side. Each purlin was 

 detailed with one of its planes horizontal, 

 and a footwalk is laid in this plane. 

 From these walks the outside roller 

 shades provided for screening the upper 

 three-quarters of the glass enclosure are 

 operated, and the glazing can be reached 

 for cleaning or repairing. Two interme- 

 diate I-beam jack-rafters in each bay 



Footwatk 



Footwalk 



nvtvralk 



.. ^_jiAr,,|-':i 





Cross Section of Berlin G>nservatory, Showing Inside Glazing. 



cast by the frame are considerably dif- 

 fused by the glass. Still another feature 

 of merit, of some importance, is that the 

 whole interior is a clear, unencumbered 

 space, which offers no obstruction to the 

 spread of plants within, such as inside 

 trusses and bracing would necessarily 

 present. 



The arrangement and main details of 



provide means for attaching the second- 

 ary purlins, which are single Z-bars, sus- 

 pended by hanger castings from the 

 trusses and jack-rafters. The Z-bars 

 virtually form a part of the skylight 

 frame, and are the only parts of the steel 

 framework which lie inside the glazing. 

 Other elements of the building and 

 equipment may be read from the illustra- 



tion, as the inside screening for the lower 

 part of the walls, the traveling ladder for 

 reaching the two tiers of heating pipes 

 hung from the trusses, and the longi- 

 tudinal passage containing radiators for 

 heating air supplied to the building. 



The floor was elaborated with special 

 care, to get thorough drainage, good soil, 

 aeration of the soil, etc. The ground 

 was excavated ten to fifteen feet deep, 

 the bottom shaped in furrows and ridges, 

 and concrete drainage gutters laid in the 

 furrows; dry stone walls covered with 

 sod were built over both gutters and 

 ridges to facilitate drainage and allow 

 the air from the outfall to enter the 

 ground. The drains were led off to an 

 open watercourse and not to the sewers, 

 so as to avoid all chance of impregnating 

 the ground with impure air, which it was 

 feared might affect the plant growth un- 

 favorably. The heater passage surround- 

 ing the whole body of soil protects it 

 against chilling. 



PLANTS FOR EDGING. 



Will you kindly give us some informa- 

 tion about the varieties of border plants 

 that may be used for formal bed edg- 

 ings? What plants are best for founda- 

 tions? Is there any writing or book 

 that treats of this subject to any extent? 

 We are located in Nebraska. 



M. & J. 



Among tender bedding plants there 

 are quite a number of plants adaptable 

 for edgings. Among dwarf foliage 

 plants, Alternanthera aurea nana (yel- 

 low) and A. brilliantissima (red) are 

 excellent. These, of course, will require 

 some pinching or clipping during the 

 growing season. For a vety low and 

 formal bordering, Echeveria metallica 

 and E. secunda glauca may be used. 

 Santolina maritima, with silvery foliage, 

 if trimmed, is also a desirable variety. 

 The various forms of coleus are among 

 the more easily grown of the more robust 

 foliage i)lants. Geranium Mme. Sal- 

 leroi is also a well known and popular 

 variety. 



In the way of tender, dwarf flowering 

 plants, Lobelia Emperor William and 

 Alyssum Little Gem are two of the best. 

 Begonias Vernon and Erfordii are hard 

 to beat where a little more height is de- 

 sired. Ageratum Little Blue Star is a 

 miniature variety. A. Stella Gurney, 

 somewhat more robust, is popular. 

 Verbenas of distinct shades of color 

 make excellent carpeting plants if they 

 can be pegged down a little. 



Any or all of the foregoing are adapt- 

 able either for borders or foundations of 

 beds. The alternanthera is the easiest 

 of all the dwarf plants to grow. 



We do not know of any book making a 

 feature of this branch of horticulture, 

 but there are frequent articles in the 

 Eeview on this subject. The Florists' 

 Manual would also prove a vfiluable book 

 for you, as it deals with the projjaga- 

 tion and culture of these and many allied 

 plants. C. W. 



Wilson, N. Y.— R. S. Church is build- 

 ing another greenhouse, about twice the 

 size of his present one. 



Fitzgerald, Ga. — Carl Thomas, pro- 

 prietor of the Thomas Greenhouses, says 

 he had a fair run of sales this spring, 

 but nothing unusual. He had considerable 

 business for the local Decoration day, 

 April 26, and after the national Me- 

 morial day. May 30, he expects to take a 

 trip back to his old home at Geneseo, 111. 



