This section is from the book "The Gardener's Monthly And Horticulturist V22", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
Having had considerable experience with grooved sash bars, I beg to be permitted to state through these columns why I failed to appreciate their efficacy. The dripping of condensed vapors never, to my knowledge, ever proved injurious to plants or seeds; it is not only of too short a duration, but also being of the same temperature as the air in the greenhouse, it fails to substantiate - yes, rather repels the supposition that any damage arises from it. No grooved bar has ever materially diminished this sort of dripping, as it is not altogether confined to the bars, but mostly where the glass laps, there the water collects when it cannot escape to the outside, which it often will as the glass does not always fit tightly at that place. There should, in no greenhouse, be any other than this sort of drip, and I am certain those built on the modern style admit of no other. I have held situations as gardener in many sections of this country, and been employed in all sorts of glass structures; none impressed me more favorably as being nearest the mark of perfection as did the greenhouses of Mr. Peter Henderson. A firm in this city has since erected several strictly on this plan.
These houses do not admit any drip from rain, for they are as tight as a drum, and I feel assured that grooved bars in these houses would be of as much use as gutters on the ceiling of a mansion, or a lightning rod down in a cellar. If the dripping is owing to the wretched condition of glazing, a better remedy ought to be resorted to than a miniature mill race, - one that will at the same time arrest any escape of heat, and once for all check this annoyance. This remedy is constantly within our means and reach - it is all in glazing which should be done in the best possible manner. My experience with grooved sash bars has convinced me that their service to carry off water was very deficient in cases of heavy rains or melting snow, particularly those on long bars, which were too small in their capacity to hold all the water, thus invariably causing an overflow, not saying anything about the dirt that accumulates in them within a season, which renders the grooves entirely useless; and to keep them clean is not only a foolish waste of time, but almost a task next to impossibility.
I even saw the attempt of adjusting small tin gutters while the glass was on, to answer the purpose of grooves, but with no better success, for it was soon discovered that more injury was done by attaching them, than they ever would make good.
It seems to me as sensible to advise the putting up of gutters on the ceiling of a dwelling when the roof is leaky. That the physical condition of plants is nearly the same as that of animals. I dare say no one doubts, also that low and moist temperature is injurious to either, is too, a settled fact; and the only means we have to ward off this injury is by making sure of tight roofs and walls, with the necessary appurtenances for heating. That greenhouses can be made sufficiently water-tight to disqualify the use and necessity of grooved bars in the future has been practically established in this section of the country, if nowhere else.
The "grooved" sash bar is an old idea, but since the more practical style of building greenhouses has been adopted, the "fluted bar" is rapidly going out of date.
I would like to occupy a small portion of space in your valuable columns in calling attention to a new style of sash bar, of which I enclose a small section for your inspection. My attention was first called to this as an improvement, by an article in the Gardeners' Chronicle, in which the merits of this style (or something similar) were illustrated and commented on. Its excellence at once struck me, and I set about finding some one to manufacture a lot for my own use. In this I experienced considerable difficulty, many of the sash men saying they knew of no tool that would make a groove of this kind; but was finally successful, and should any of your readers experience the same difficulty, will be pleased to give them the names of the parties who are making them for me.
I might enlarge considerably on the merits of this bar with the side grooves for carrying off the water, but doubtless you and all others interested in the construction of greenhouses will appreciate them fully without further remarks from me.
[Bars like these noted by Mr. Smith, have been in common use about Philadelphia for some years, where the sash factories have had the proper tools to make them. They are highly appreciated by those who know their value, and it will be a service to Western plant growers to know that they can be had there now as well as here. We have marked by white lines a portion that would be better cut away. It would add materially to the light of the house without interfering much with the strength of the bar. Perhaps the upper part would be better sloped for the same reason, though we never saw it done. It would weaken the bar but little, while a very little here makes a great difference in the light in the house. In these days when we use putty only beneath the glass for bedding it, there is no use for any wood above the glass beyond what is to hold the sprig used for fastening the glass. - Ed. G. M].