THE FLORISTS MANUAL. 



J33 



greenhouses to afford the best conditions 

 for the gravity system. We know of such 

 places in our locality, and one well 

 known place in Philadelphia where such 

 circumstances exist. It may be economy 

 in installation to adopt the gravity sys 

 tem. But where there is not such a 

 slope, and if the site of the boiler-house 

 is about the same level as the greenhouse 

 floor, to adopt the gravity system you 

 would have to excavate ten or twelve 

 feet, then perhaps drain the hole at great 

 expense. Under these circumstances I 

 must pronounce this excavation, with all 

 its terrible inconveniences and expense, 

 the height of folly. It is absolutely un 

 necessary. I have never known anyone 

 using the high pressure system to con 

 vert their system into gravity, but I do 

 know men of large experience who, after 

 they had their boilers installed down in 

 a deep hole, changed to the pressure sys 

 tem and expressed themselves as being 

 foolish for ever going to the expense of 

 excavation, hauling out ashes, etc. 



Now suppose you do use the gravity 

 system. The boiler should be low 

 enough so that the return pipe in your 

 houses, the pipe that carries the con 

 densed steam, is four feet above the 

 level of the water in the boiler, and if 

 it is six or eight feet so much the bet 

 ter. 



Scarcely any two ranges of glass are 

 built alike, so it would be impossible 

 to give any definite directions for ar 

 rangement of pipes. Under the gravity 

 system the main steam pipe leading 

 from the boiler needs to be larger than 

 with the pressure system, because the 

 steam is not so dry and hot. For 

 20,000 feet of glass surface we think 

 that not less than a 6-inch flow should 

 be used, while we have proved that a 

 3-inch under pressure is large enough. 

 The main pipe can either run along the 

 end of the range of connected houses, 

 or up one of the houses in a trench free 

 of water. In either case it should be 

 well covered with asbestos, or you will 

 waste heat as well as have too much of 

 it in certain parts of the house. Your 

 main steam pipe can always be reduced 

 in size as its steam is used. If you 

 start with a 4-inch pipe, after sup 

 plying steam for two houses it can be 

 reduced to a 3-inch, and after two more 

 are served to a 2-inch. I don t know 

 that it makes any difference whether 

 your main pipe rises gradually and even 

 ly, or whether it drops slightly to the 

 farthest point, but would prefer that it 

 rose slightly. There is a difference of 

 opinion as to where the heating pipes 

 should be placed. We lately learned 

 the opinion of a most successful rose 

 grower who said all he wanted were 

 pipes on the side walls. We know equal 

 ly successful and larger growers who 

 run a 1^4-inch around the edge or side 

 of every bench. And I am inclined to 

 believe there is a more even and better 

 distribution of heat when the pipes are 

 well distributed. Few growers of roses 

 or carnations nowadays advocate heat 

 ing pipes beneath their benches, but a 

 pipe running along the side of a bench 

 or bed is a different thing. Hook plates 

 fire now being made to build into the 



low brick or cement walls of semi-solid 

 beds and there I think is a good place 

 for a heating pipe. Some who use 

 steam will run five or six 1*4 -inch pipes 

 up the length of the house and provide at 

 the farther end one 1^-inch or 1%-inch 

 return for the condensation. In anything 

 less than 300 feet this is not the best plan. 

 If there is a drop of a few inches to 

 the farther end of the house and the 

 same drop bacK, then run two or three 

 flow pipes, or more as the case may be, 

 and the same number returning. The 

 latter pipes, which we will call returns, 

 will radiate as much heat as the flows, 

 for with three or four pounds pressure 

 they will be full of live steam and there 

 will be no condensing till the steam en 

 ters the main return, which is in most 

 cases on or just below the surface of 

 the house. 



Although not an advocate of overhead 

 pipes, I have found in the use of steam 

 that two 1^4 -inch pipes, one on each side 

 of the house, two or three feet below 

 the glass, are a great help in very severe 

 weather. We have winds and frost and 

 blizzards occasionally when you can al 

 most feel the frost falling from the 

 glass. Then it is that the overhead 

 pipes are a blessing, moderating the cold 

 before it strikes the plants. In more 

 favored climates these overhead pipes 

 may not be necessary, but they cost but 

 little. We run a pipe along over the 

 plants to a farther end of the house 

 and, dropping it there, return along the 

 side of a bench. 



I think in some establishments there 

 are not valves enough used. There 

 should be a valve on every run of pipe, 

 not only on the end where you let in the 

 steam but on the end where it enters 

 your main condensed. If you have oc 

 casion to turn off a certain run of pipe 

 and have only a valve at the feed end, 

 you will by closing that valve soon have 

 a vacuum in the pipe, because the steam 

 will soon condense. Then the pipe fills 

 up with any water there is in the system. 

 This does no harm at the time, but when 

 occasion arises to run that pipe again 

 you have a lot of cold water to dispose 

 of and that must go back to the boiler, 

 needing more fuel to raise the water to 

 the boiling point. Put on valves where- 

 ever there is any chance of their being 

 useful. In case of a cracked pipe or a 

 broken joint through expansion, the ab 

 sence of a valve may cause you to shut 

 down your whole system while repairs 

 are made. Those using cast iron or 

 metal gutters will find a steam pipe run 

 ning along a foot beneath the gutter 

 will make a considerable difference in 

 the disappearance of the snow. I think 

 now I have said enough on this system 

 and will proceed to consider the other, 

 which we called high pressure and with 

 which I have had much more experience. 



High Pressure System. 



In this system it makes no difference 

 whether the floor of your boiler-house is 

 on the same level as the greenhouses or 

 two feet below or two feet above. It 

 will make no difference in the working of 

 the system. In my case the ground at 



the north-east end of the range happened 

 to be two feet lower than the average 

 level of the greenhouse site. I mention 

 this because I think the north-east is 

 where a building such as a boiler-house 

 necessitates will cast the least shade and 

 do the least harm. Being almost on a 

 level with the surrounding ground the 

 fuel can be wheeled to the furnace doors, 

 but better than that, the ashes can be 

 wheeled out. There is no iron ladder to 

 climb down and break your neck on 

 Christmas eve or other occasions when a 

 faltering step is excusable, no water or 

 stopped up sewer to fret and annoy. 

 Now all there is about this system be 

 sides saving labor and expense in in 

 stallation is that you carry from forty 

 to sixty pounds of steam on the boiler 

 all the time. One practical friend said 

 he carried sixty-five pounds and believed 

 it was more economical of fuel than for 

 ty pounds, and by the use of a con 

 trolling valve the pressure is reduced 

 one, two, or five pounds on your system 

 of heating. The controlling valve recom 

 mended to us was the Mason, made 

 in Boston, Mass., and not once in three 

 years use has there been the slightest 

 hitch or trouble with it. The slightest 

 turn of the brass key on top of the valve 

 will increase or diminish the quantity of 

 steam passing through the valve. A 

 small steam clock connected with the 

 main steam pipe a few feet beyond the 

 controlling valve will tell you how much 

 steam you have on your heating system. 

 In our case the main steam pipe leaving 

 the boiler is only a 3-inch, carrying of 

 course the fifty pounds of steam till it 

 reaches the controller, which in moder 

 ately cold weather is set a^ three, in 

 severe weather at five or six, and this is 

 enough to carry the steam in some of the 

 houses for full 500 feet. It is just 

 worth mentioning here that while you 

 have fifty pounds of steam in your 

 boiler, if a sudden storm comes up or a 

 sudden fall of temperature, all of which 

 often happens, there is no great commo 

 tion at the fire door but simply a turn 

 of that little brass key on the controller 

 and the opening of a few valves. You 

 have the reserve steam at all times and 

 it costs no more to keep it there than it 

 does to keep up two pounds of steam on 

 your gravity system. 



Now, whatever arrangement of heat 

 ing pipes you have there will be one pipe 

 you call your main return, which in the 

 gravity system empties the condensed 

 steam into the boiler. In the pressure 

 system it empties into an automatic 

 steam pump or a trap. It is my duty 

 to be honest, so I must confess I have 

 no experience with a steam trap of any 

 make, but I have watched them working 

 and have consulted practical men who 

 have used both the trap and automatic 

 pump and in every case they gave a 

 strong preference for the pump. I un 

 derstand that a trap does not work un 

 less you have five or six pounds pressure 

 on your heating system. In the case of 

 the pump you can have but one on your 

 radiating pipes. That will make no dif 

 ference because your pump is supplied 

 by a small pipe (1-inch will do) from 

 top of your boiler where it gets what- 



