Archive image from page 112 of Cyclopedia of American horticulture, comprising. Cyclopedia of American horticulture, comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers and ornamental plants sold in the United States and Canada, together with geographical and biographical sketches, and a synopsis of the vegetable kingdom cyclopediaofamer03bail Year: 1906 aREENHOUSE passing through such lenses, and it is not difficult to see that the same effect may be produced by similarly im- perceptible variations in the thickness of sh
Archive image from page 112 of Cyclopedia of American horticulture, comprising. Cyclopedia of American horticulture, comprising suggestions for cultivation of horticultural plants, descriptions of the species of fruits, vegetables, flowers and ornamental plants sold in the United States and Canada, together with geographical and biographical sketches, and a synopsis of the vegetable kingdom cyclopediaofamer03bail Year: 1906 aREENHOUSE passing through such lenses, and it is not difficult to see that the same effect may be produced by similarly im- perceptible variations in the thickness of sheet glass. That this is the ease has been conclusively shown by the series of experiments before mentioned. These also show that burns on plants, caused by defective glass roofs, occur in lines and not in isolated spots, burns of the latter description being usually the result of a GREENHOUSE 691 PARALIEU CONVERGENT RAYS RAYS t ⢠â .' ' POINTS OF REFRACTION _ FOCAL DISTANCE 10 FT. weakening or deterioration of tissue, due to carelessness in the matter of ventilation, humidity of the atmos- phere and water, and temperature of Greenhouses, rather than to defects in the glass of roofs. If, therefore, it is not possible to obtain glass of uni- form thickness with certainty, it may be found cheaper and often fully as satisfactory to purchase the lower or common grades of double thick glass, using in the roof only those panes which show, after testing in the sunlight for foci, an entire lack of the prismatic charac- ter which makes them dangerous to plants grown under them. J. c. Blair. Greenhouse Heating,âIn all sections in which the temiiimture dmiis below the freezing point, it is neces- sary tn priivide some artificial means for heating Green- houses. Nearly all modern structures are warmed either by steam or hot water, although hot air flues are occasionally used. While hot water is preferred for small ranges of glass, as it can be depended upon to furnish an even degree o
Size: 2090px × 957px
Photo credit: © Bookive / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: 1900, 1906, americana, archive, bailey_l_h_liberty_hyde_1858_1954_ed, blc, book, bookauthor, bookcentury, bookcollection, bookcontributor, bookdecade, bookpublisher, booksubject, bookyear, drawing, gardening_dictionaries, historical, history, illustration, image, miller_wilhelm_1869_joint_ed, new_york_doubleday_page_company, page, picture, plants_north_america_encyclopedias, print, reference, umass_amherst_libraries, vintage
