The numerous letters which reach us show the intense interest the subject has for those who have greenhouses to warm. Most of the objections to it made in the past are being removed. One of these objections was that we could not heat a house rapidly enough - we have to wait till we get up the steam; but those of us who remember how long it took to warm up a house heated by flues, or even by hot water, begin to believe the old system is a case of " the more haste the less speed." After the steam is once up a house can be rapidly warmed hundreds of feet away.

In reply to Mr. E. Holley's question, page 39, February number, regarding steam heating in greenhouses, I desire to say:

First

In a greenhouse 20x100 feet, or longer, it will require a coil of six radiating one-inch pipes on each side and through the entire length of the house, to maintain a temperature of 650 during a severe cold storm, when the thermometer goes down to 150 or 200 below zero. The main point in putting in steam-pipes is to have plenty of stop-valves, so that heating can be regulated according to the demand of the weather. During ordinary weather, say when the thermometer goes down to 200 or 24P below freezing point, then two pipes on each side of the house would be sufficient to maintain the desired temperature.

Second

My opinion is that two one-inch pipes are better for radiating heat than one two-inch. I explain it thus: The circumference of two one-inch pipes is greater than that of one two-inch, therefore more heating surface, and consequently more heat.

Third

As to the heating capacity of a certain sized boiler the most reliable information can be obtained from a competent steam-fitter. Ascertain how many feet of pipe it will take to heat your house, or houses, and he can easily tell how large a boiler it will require.

Fourth

I find that steam-heating costs about one-fourth more in fuel and double the amount of labor in attending to same, than hot water heating.

Fifth

I find no difference in its working, whether the pipes are in an ascending or a descending position - the condensation of steam in the ascending pipe does not seem to cause any trouble. One of the chief points is to have plenty of power in the boiler, and be careful to keep you pipes above the water-level of the boiler.

Sixth

Our boiler requires attention every two or three hours. It would sometimes last longer, but it is so unreliable that it is safest to watch it regularly. I find it to be the same with nearly all local florists who have steam-heating in use.

Seventh

The style of boiler we have in use is a horizontal tubular; it is claimed that these have the most heating surface, and are, therefore, recommended to be the best.

The above are as accurate answers as I can give from the result of our experiment, and trust it will enlighten Mr. H. and others interested.

It may be agreeable to some of the readers of the Monthly to learn how we have our steam-pipes arranged, and how our combined steam and hot water heating is managed.

Our greenhouses, now twenty in number, covering an area of more than 50,000 square feet of glass, are heated by six No. 17 and two No. 16 of Hitch-ings & Co.'s corrugated fire-box boilers, and two of Meyers' improved hot water boilers. To these we have attached about 12.000 feet of four-inch pipes. As we needed all these houses to grow cut-flowers and could not heat them to a desired temperature for that purpose, and were about to make additions last summer, we decided to put in a steam boiler in order to tests its merits. The boiler is of above-described style, 3 1/2 feet in diameter by 14 feet long, with 54 flues. To this we have attached about 6,000 feet of pipes of various sizes. The four-inch supply pipe leads through a house 20x128 feet; from this branches lead into four different houses with a coil of three one-inch pipes in each house, ascending from the supply pipe. These houses are 20 feet wide and the steam-pipes maintain a temperature of about 55°. When the thermometer goes down to 260 below freezing point in colder weather we add hot water pipes, of which we have eight in each house.

In this way we use the steam in fourteen different houses.

Then we have another three-inch supply pipe leading to four houses 10x120 feet each, heated by steam exclusively. In each of these houses we have a coil of three one-inch radiating pipes descending from the supply pipe. The condensed steam is led to the boiler with a one-inch pipe descending to boiler. With all the pipes in use we can maintain a temperature of 480 when the thermometer goes down to 20° below zero.

As steam-heating is now attracting considerable attention and is the topic of conversation among florists, I will proceed to discuss a few important questions on the subject.

First

Is steam-heating really better and cheaper than hot water? As far as our experience teaches we must say no. I will first take into consideration the cost of construction. It is very true that steam can be put in cheaper than hot water, but the question is : Will it last as long? Time will tell! Now comes fuel and labor. It was claimed by one or two local writers that steam costs less in fuel and is better than hot water. I would ask how can these gentlemen make such an assertion when neither of them ever had any hot water heating and do not know what it is. Good steam-heating may be as good as hot water, but I feel safe in saying that it is not a particle better.

And even if it is as good as it is claimed to be, and better than hot water in all points, one more important question is: Will steam heat be as agreeable to plant life as hot water heat? I will mention one case. In the four houses heated by steam exclusively we have carnations. They were looking splendidly until the end of December last. At that time heavy firing commenced and we soon noticed that they were not doing as they should. Although kept quite cool they showed a feeble growth. We put in a lot of cuttings from them and soon found that it was very difficult to root them.

On further examination we found that the wood was "tough;" also that the flowers, after being open two days, would fade away, while those in the other houses heated by hot water would last eight or ten days. Does it not look as if steam had something to do with it?

In your February number, Mr. E. Holley, Hudson, N. Y., asks for information concerning steam heating. The use of steam for heating greenhouses is comparatively new, and those who desire to use it will probably find it the cheaper plan to see the different establishments that use steam or have a good steam fitter to do all the work; give written contracts and warrant everything to satisfaction, rather than attempt the fixing themselves.

My own experience was a dear one, costing over $5,000. I have two boilers, combined about 25 to 28 horse-power. They heat six greenhouses, 64 by 22. feet each and dwelling with eight large rooms; each room has a heater similar to heaters in public buildings in large cities. This dwelling is connected by a narrow hallway with shed of greenhouses. The hired hands have their rooms connected with this shed. The main steam pipe goes through these rooms to the dwelling. My experience shows that the horizontal boilers are best for greenhouse heating. The upright boilers are well enough in hotels, boarding-houses and large dwellings, where they can be put in the cellar. In greenhouses they would have to be low enough to keep pipes 2 1/2 feet to 3 feet above the water line. Of course pipes must be above the water line on the horizontal boiler as well, but on account of it being a horizontal, it does not need to be so deep in the ground. One of our florists here has a self-working sucker on the boiler, so the boiler can be put on the level ground, and pipes are all below the water line. This sucker (or whatever it may be called) draws all water in the pipes back to boiler and leaves the steam dry.

So far this works well, and if it never gets out of order it would be good for those who cannot have the boiler deep enough on account of water. Greenhouses the size of mine must have eight to ten one inch pipe all around in each greenhouse to keep it 6o° to 650, when it is 150 below zero outside. I have main pipe four feet above water-line, running through shed, and each house connected with one pipe 1 1/2 inch from the main, which is two-inch. This pipe is connected with a coil of four one-inch pipes all around walk back to shed where the four pipes are connected to a manifold, the same as the conneccion to a manifold where it starts from the main pipe. The manifold at the end of the pipes has an air-cock on top; underneath is the return of one-inch to the boiler, or a main return can be led back to boiler in the form of a two-inch pipe, and all small one-inch returns connected to this. All my houses are now arranged with pipes as above. As to how long steam will last, or how often a boiler must be looked after, night or day, any one can see that a steam boiler must be looked to more than a hot water one. When fire goes down steam goes down too. A steam boiler must be looked after at least every three hours in a cold snap like we had this winter.

I had two hands firing at night; while one slept six hours the other fired. Taking it all in all - leaving out pipes - hot water is the cheaper, but for a large business, or even from five large greenhouses up, steam is cheaper, all counted. For a few houses hot water would be my choice. But, as I am situated now, steam is a great saving to me. On my dwelling alone I save from $100 to $150 in one winter on base burners and coal for them. I expect to burn sixty tons of best hard coal this winter.

In your February number, Mr. E. Holley, of New York, asks some questions regarding steam heating. I would say that I would not advise the putting in of smaller pipe than 1 1/2 or 2-inch size. His house being, as he says, 100x20 feet, and 5 feet in height, it gives say 12,000 ft. of air surface. To be heated to a temperature of 65° it would take three rows of 1 1/2-inch pipes, or two of 2-inch, on each side of the house, allowing sufficient heating surface for extreme cold weather. Allowing 1 1/2 pounds steam in low pressure boilers, the greater the pressure the higher the temperature. Low pressure, with automatic dampers and valves, is a more economical system than that of hot water. The latter calls for the heating of ten times the amount of water that steam requires. All pipes should have a gradual fall from boiler of 1 1/2 to 2 inches in every 10 feet of length, then it requires no pressure to force the water through the pipes. See that the pipes furthest from the boiler are not less than 14 inches above the water line of it; - more will be better. The return pipes must descend to boiler, connecting with the bottom of it. Such a house will take a boiler containing a heating surface of 130 feet, or of about six horse power. One of twenty horse power would heat four such houses.

All things being equal an ordinary boiler will answer the purpose. It is better to have a boiler with automatic arrangement so that the pressure and temperature will be uniform. Leaving a good fire at 10 p. M., it would need no attention until 7 A. m. the next morning.

Steam Heating In England

In conversation with several practical horticulturists in England, a month or two ago, I found they had a strong prejudice against heating greenhouses by steam. They were not at all surprised that the method gave satisfaction in America and was being adopted to a considerable extent by our florists ! Don't be too egotistical, John, American florists may know quite as much as you give them credit for.

Steam Heaters

These seem to be growing in popularity. Messrs. Hovey & Co., of Cambridge Mass., Lonsdale & Burton, Germantown, and the Agricultural Department at Washington, have recently set up steam boilers from the Exeter Works; and the old and extensive cut-flower establishment of L. C. Baumann, at Germantown, will introduce steam heating, employing however a second-hand locomotive boiler to heat up with.