414 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



[ June 9, 1863. 



1815 to 1860, has been divided into four ten-year periods and 

 one six-year group. By including ten years, the extreme 

 jumps of temperature between one year and another partially 

 disappear ; whilst the five mean groups are ample to shovr that 

 no radical change has taken place. 



We might have gone back much further, but were unwilling 

 to admit any evidence on which we could not place the most 

 perfect trust ; and thermometer readings ant-rior to the com- 

 mencement of our table we did not consider so accurate as those 

 of the later date. 



The mean temperature of the ten years from 1815 to 1824, 

 both inclusive, was 49.8°, for the next decade it was 50.4°, for 

 the following 49.2°, then 49.8°, and for the six years it was 49.0°. 

 Here we perceive no difference to any material amount, and we 

 might for all practical purposes consider the readings to be 

 identical, which, were the series sufficiently long, no doubt they 

 would be. 



But, it may be remarked, if the winters have become warmer 

 and the summers colder, no difference may be shown between 

 the yearly average temperatures of one ten years and another ; 

 although the effect of such a change in the seasons would be of 

 the utmost moment to the progress of vegetation. True ! and 

 to guard against this error, let us examine each month, taking 

 the mean of every ten years for each month of the year ; we 

 shall then see if the individual months have altered at all, or if, 

 on the contrary, each has received, on the average, its normal 

 amount of heat. 



Table showing the average monthly temperature in ten-year 

 groups, from 1815 to 1860 inclusive :— 



Tears. 



Jan. Feb.'llar. 



Apl. 



May 



Jan. 



Jul. Aug Sep. 



. . . 



Oct. Nov 



Dec. 









c 



1815 to 1824... 



38.1 '40.1 



43.2 



47.2 



53.0 



58.2 



61.1 61.5 159.0 



50.8 45.5 



40.4 



1825 to 1834... 



37.3 39.9 



43 



48.(1 



54 6 



60.2 



64.0 61.6 J57.2 



52.1 43.9 



42.0 



1835 to 1844... 



37.8 38 8 |42.4 



45.9 



53.2 



59.1 



81.5 61.9 56.9 



49.5 43.9 



40.0 



1845 to 1854... 



39.2 39.7 141.2 



46.2 



53.1 



59.0 



G2.3 61.0.56.6 



49.5 44.3 



40.4 



1855 to 1860... 



38.1 37.3 



41.3 



45.7 



51.9 



60.0 



62.4 62.4:57.1 



51.4 41.7 



39.2 



Looking over this table, the eye fails to discern any approach 

 to a descending tendency, or, indeed, to discover any periodicity 

 whatever in the results. Here is a number above, there one a 

 little below the average, but nothing to indicate any regular 

 march either of increase or decrease. 



If it be necessary, let us make out another table, in which we 

 will calculate the average temperature of the seasons for each 

 decade. The following will then be the statement : — 



Table showing the average temperature of the seasons, in ten- 

 year groups, from 1815 to 1860 inclusive : — 



Years. 



Spring. 



Summer. 



Autumn. 



"Winter. 



1815 to 1824 



43°. 5 

 43.7 

 42.7 

 42.4 

 41.4 



'a 

 57.4 

 59.6 

 57.9 

 5S.1 

 58.1 







57.1 

 57.0 

 56.1 

 55.7 

 57.0 



41.3 



1825 to 1835 



41.2 



1835 to 1844 



40.6 



1845 to 1854 



41.3 



1855 to 1860 



39.7 







Here is a striking uniformity between the mean temperature 

 of one decade and another. Were the series sufficiently long, we 

 have no hesitation in saying that even these slight inequalities, 

 which exhibit no law amongst themselves, would disappear, and 

 the number expressing the temperature of either season for such 

 a period would be identically the same for all averages including 

 the same number of years. It is needless to remark that, m 

 compiling tableB of this kind, the most rigorous exactitude is re- 

 quired : one false reading would throw a doubt over the entire 

 table, as would also a single inaccurate observation. 



To sum up in a few words, the only conclusion we can arrive 

 at is, that there has been no alteration in the temperature of this 

 country, nor have the seasons changed their characteristics. 

 "Seed time and harvest" have never ceased nor exhibited any 

 tendency to encroach one on the other ; the laws of meteorology 

 are as stable as those of astronomy, and the regularity of the 

 heavenly bodies is not more Btrictly maintained than that of the 

 recurrence of the phenomena of climate. We shall be glad to 

 see the popular error, that the winters are warmer and the 

 summers colder than they used to be, fade and die out ; such a 

 belief is calculated to do much barm, and therefore, on the 

 ground of expediency, should be thrown aside, even if the bare 

 recommendation that truth always brings with it were not suffi- 

 cient to secure a place in all men's minds. — (Mark Lane 

 Mispress.) 



ALYSSUM SAXATILE COMPACTUM. 



Dweing the month of April, when riding on one of the omni- 

 buses which run from the town of Leeds to the out-townships, I 

 saw in one of the villa gardens which line the road some plants 

 of Alyssum quite different from any which I ever saw before ; 

 their dwarf growth and close compact-flowering habit was quite 

 the reverse of the plants in my garden at home. Thinking that 

 the soil had something to do in the matter, and not being able 

 to make inquiry on ,the spot, I allowed the thought of them to 

 pass out of my mind. Since then, when on a visit to Shipley, 

 near Bradford, walking with a friend past the Shipley Nurseries, 

 and having a few minutes to spare we walked into the nurseries. 

 Here, again, I met with the dwarf plant, labelled Alyssum 

 saxatile compactum, in full flower, the flowers quite covering the 

 leaves, and forming an object very pleasing to look upon. The 

 grower of hardy herbaceous plants will not make a mistake in 

 growing this early spring-flowering plant, and the bedder will 

 do well to grow this shrub in his beds at a season of the year 

 when they are naked and dull. It is a plant which must be a 

 favourite, even if it to some growers be an old favourite. I 

 would have secured some plants, but Mr. Dean was engaged 

 with some customers, and the Bhort time allowed me having 

 rapidly flown away, I was forced to hurry off empty-handed. — 

 Rustic Bobix. 



HEATING GARDEN STEUCTUEES. 



(Continued from page 401.) 



Flees. — In houses of some size — say 36 feet by 18 feet, where 

 a forcing temperature is required to be kept up, two flues are 

 required ; the one, a single flue, takes the front, and the other 

 makes two or three journeys along the back. The flues here are 

 constructed of brick dished in the middle like a press-brick, but the 

 hollow penetrates fully an inch into the brick. Three of these 

 placed on edge form the Bides of the flue. The bottom of the 

 flue was formed of bricks 15 inches square by 2 thick, and these 

 were laid on a single thickness of common brick at the joints of the 

 flue-bottom only. These bearers were laid on a foundation 

 of bricks levelled with the plumb-bob. The covers for the flue 

 were 15 inches square by 3 thick, dished out like the side 

 bricks, and would hold when filled nearly three pints of water 

 each. The flue at its entrance into the house was formed for a 

 yard of fire-bricks at the sides and top, and then fire-tiles were 

 used for covers a yard further, which part was entirely covered 

 by flagstones to prevent the heat from scorching the plantB in 

 the vicinity. Bear in mind this was the front flue passing along 

 both ends and the front of the house. The furnace was 2 feet 

 3 inches long, 1 foot 3 inches wide, and 1 foot 3 inches high 

 above the grate. It was built entirely of fire-bricks, and the 

 top was arched. The top of the furnace was level with the 

 bottom of the flue, so that the smoke or heated air rose 1 foot 

 3 inches from the fire, after which it went at a dead level, and 

 rose no more until it entered the chimney. The flue at the back 

 of the house was similarly constructed, only it went three times 

 along the back, and like the front flue was covered with dished 

 bricks. In the hollows water was poured when a moist heat was 

 desired, and pieces of stone were placed therein, on which pots 

 containing Orchids were placed. I have seen some very fine 

 plants of Bletia Tankervillise, and other old-fashioned Orchids, 

 grown in this manner, and French Beans were regularly forced, 

 the pots being placed on a wooden trellis made on purpose. 

 Some of the finest Amaryllises were grown on the front flue, 

 and bo place was ever more calculated to suit them than this. 

 The plants were in the midst of a moist atmosphere when 

 growing, and literally baked when at rest. The position was 

 marked out by Mr. Herbert, of Spo£forth, near Wetherby, 

 as a fit and proper place for that tribe of plants, and I believe 

 the greater part of the plants were had from him. I regret to 

 say that they have lately been thrown away as unworthy of a 

 place amongst so many fine plants as we have at present in our 

 hothouses. 



Now, those flues were made about 1820, the houses being, I 

 think, completed in the autumn of 1821 ; and they cost £9 Us. 

 the pair, labour and everything being considered. Five of such 

 houses with similar flues were put up at the time, so that the 

 cost of the heating apparatus alone was £47 15s. The range was 

 divided into four Pme-stoves and a vinery. There were Vines 

 in three of the other houses. 



Fine Grapes were grown in those houses, specimens of Black 





