April 2, 1874. 1 



JOURNAL OF HORTICULTUEE AND COTTAGE GARDENER. 



209 



WEEKLY CALENDAR. 



Day 



of 

 Week. 



Th 



F 

 S 



S0N 



M 

 Tn 

 W 



APRIL 2—8, 1874. 



Meeting of Litmean Socciety, 8 p.m. 

 Good Friday. 



Easter Sunday. 

 Easter Monday. 

 Twilight ends 8.44 P.M. 

 Meeting of Society of Arts, 8 p.m. 



Average Tempera- 

 ture near London. 



Rain in 

 43 years. 



Day. 



,■57.8 

 57.1 

 56.7 

 57.0 

 67.0 

 57.7 

 66.1 



Night, 

 8(T.7 

 35.7 

 35.7 

 36.7 

 3G.9 

 86,8 

 35.8 



Mean. 

 4B.9 

 4G.4 

 46.2 

 46.0 

 47.2 

 47.8 

 46.0 



Davs. 

 21 

 20 

 17 

 21 

 14 

 21 

 23 



Sua 

 Rises 



m. h. 



85 at 6 

 33 6 



San 

 Sets. 



m. h. 

 S2a(6 



34 6 



35 6 

 87 6 

 89 6 



41 6 



42 6 



Moon 

 Rises. 



m. h. 



19 7 



80 8 



43 9 



67 10 

 morn. 



12 



22 1 



Moon 

 Sets. 



m. 



53 

 4 

 16 

 32 

 53 

 21 

 2 



Moon's 

 Age. 



Davs. 

 15 

 16 

 17 



18 

 19 

 20 

 21 



Clock I Day 

 before ot 

 Sun. Y<ar. 



From observations taken near London during forty-three years, the average day temperature of the week is 57.0" ; and its night temperature 

 35.3'. Thegreatest heat was 10\ on the 7th, 1859 ; and the lowest cold 21= on the 6th, 1831- The greatest fall of ram was 1.19 inch. 



BOILBKS AND HEATING APPARATUS. 



T is not ■without muoli hesitation that I give 

 an opinion upon boilers, inasmuch as, with 

 the exception of the Potato disease, I do not 

 know of anytliing connected with horticul- 

 ture that has caused more discussion or given 

 rise to more widely opposed ideas. Ever 

 since garden structures were first heated by 

 hot water the character of the boiler, as well 

 as that of the pipes, has been a source of 

 controver.sy, and it is as far from a clear 

 solution as it was twenty years ago. True, the character 

 of the piping has been less discussed of late, and may be 

 said to have settled down into so many feet of tubing of 

 4 inches in diameter inside, technically called 4-uach pipe. 

 Eival boiler manufacturers, in setting forth the merits of 

 their respective apparatuses, generally speak of the many 

 hundred feet of such pipes their boilers are capable of 

 heating, and some of the assertions made approach very 

 nearly to the marvellous, but we seldom hear of those 

 who have adopted such extraordinarily good bargains 

 speaking of their economy of fuel. Let us now take a 

 glance at what has been done in the way of warming 

 buildings by hot water, and review some of the changes 

 that have taken place in public opinion on the subject. 



My earliest acquaintance with the heating of garden 

 structures by hot water commenced in 1829, and a year 

 or two afterwards I remember noticing a parish church 

 of an average size being heated in the same way. The 

 plan in those days was for the pipes to be large — some 

 8 or 10 inches in diameter, and the flow pipes to be laid 

 perfectly level, with openings at places in the tops of the 

 pipes, where, by taking off the lid, the flow of the water 

 could be seen ; and it was thought that the circulation 

 was quickest when the top pipes were only about three- 

 fcurths full. The boiler in those days was also a 

 capacious vessel, often square, with the bottom slightly 

 arched, but not so much so as in the modern saddle, 

 but it was doubtless the parent of it. A flow and a re- 

 turn pipe were placed one over the other at its sides or 

 end. The boiler, I may add, had a loose-fitting lid at the 

 top large enough for a man to get through, and was only 

 filled with water sufficiently high to allow the flow pipes 

 to be, as before stated, three-quarters full — in fact, the 

 water was generally put into the pipes where the quan- 

 tity could be seen. Simple as this plan may seem to be, 

 I have a clear recollection of two lean-to vineries being 

 li-eated in this way with as little trouble and in quite as 

 efiicient a manner as any I have had to deal with since, 

 and this was some time about the passing of the first 

 Reform Bdl. 



Subsequently other schemes were tried, differing more, 

 it must be confessed, in the way of arranging the pipes 

 or their substitutes than in the boilers ; for patents for 

 the open gutter as well as the tank were taken out, 

 with, I expect, loss and disappointment to all parties ; 

 while square, flat, and half-circular pipes had their re- 

 spective advocates. Neither was cast iron the only sub- 

 No. 679. -Tot. XXVI., New Series. 



stance employed for the conveyance of the heated liquid, 

 for copper, tin, and sheet iron were used. I cannot say 

 that I ever saw the first-named, but I remember a forcing 

 house heated with water that had to travel through closed- 

 in boxes or gutters of sheet iron, not much more than 

 1 inch wide by a foot deep, looking exactly like as many 

 inch boards set on edge, the idea being that the more 

 outside surface there was the better ; but it did not work 

 well — not half so well as a plan something like it in which 

 the water travelled in a continuous vessel hke a 3-inch 

 plank laid on the flat. This method was supposed to be 

 better adapted for forming a shelf for plants, or for any- 

 thing that was wanted ; and its heating qualities seemed 

 to be satisfactory, for, having occasion to visit the place not 

 long ago, I found the apparatus still working after a service 

 of thirty-five years. Other fancy pipes or modes of heat- 

 ing came into vogue for a time. One in which very small 

 pipes of less than an inch bore were employed was strongly 

 advocated ;• this was called the high-pressure system, in 

 consequence of the water being closed in, there being no 

 ventilation nor outlet, but a sort of au--tight chamber of 

 moderate dimensions in which the steam might condense 

 and return again through the pipes, its advocates assert- 

 ing that it was unnecessary to replenish with water, as 

 none escaped. This plan is in general too costly for 

 garden structures, and has been limited to dwelling-houses 

 and public buOdings ; but the pipes being liable to get 

 much hotter than those of other hot-water apparatus, it 

 has been pronounced dangerous, and some insurance 

 companies object to its use, or insist on the pipes being a 

 respectable distance from timber. This, however, is not 

 always adhered to, for I noticed a new church heated in 

 this way not long ago, where the pipes almost touched the 

 woodwork. Still, this method is not adapted for garden 

 structures, and the advocates of the tank system seem 

 also now less loud in their praises of it than they were 

 some twenty years ago ; so that it may be taken for 

 granted that with few exceptions the bulk of the hot- 

 houses now erected and heated by hot water are warmed 

 by 4-inoh pipes, which seem to have usurped the place of 

 all other kinds, and the ingenuity or experiments of those 

 desirous of improving heating apparatus would appear to 

 be now all centered in boilers. 



Of boilers the last twenty years have given us great 

 variety, and each form having its advocates, it is not an 

 easy task to give an opinion on their respective merits 

 beyond the hint to those about erecting them and who are 

 not personally versed in the matter, that they had better 

 not adopt any that is asserted to effect a great deal of 

 heating with about one-fourth of the coal required by a 

 good saddle boiler, for it is likely they will be disappointed. 

 I do not mean to say that the saddle cannot be improved, 

 but when the saving of fuel amounts to so large a pro- 

 portion as three-fourths of the quantity, suspicion may 

 justly be aroused, and the issue often warrants it. A 

 saving of a smaller proportion ought to sufiice for all 

 reasonable testimonials of merit. Notwithstanding the 

 vaunted qualities of new and improved boilers, a pound 

 of coal can only give off a certain amount of heat, and 



No. 1S31— Vol. LI, Old Series. 



