THE GARDENERS' CHRONICLE 



01 



■•red 



""" '" "" """ ~" ■""""■ "" "' ,r - so g re at a difference as 1 expected, on comparing the 



average mean temperature of the months of November 

 and December, 18 54, and January, 1 855, with the corre- 



The observation applies chiefly to 



those 



seen on uj» «« 

 boose plants, 



EaxDpean countries, as i am miiy aware tiiat there are 



idealities in the southern hemisphere which enjoy 



meteorological conditions even more favourable for the 



rth of plants, which are natives of warm temperate 



E»te«; e. n* } Van Diemen's Land, and even the 

 id of Madeira in Europe. If this be admitted, it 

 follows that Ireland must be influenced by some peculiar 

 meteorological circumstances, which do not affect other 

 countries situated in the same parallels of latitude ; or 

 falling under the same isothermal lines on the 

 nrface of the globe. The prevailing cause, I presume, 

 arise* from the influence the sea exercises in equalising 

 temperature in all countries which are broken up with 

 golfs and peninsulas, compared with those in the interior 

 of compact masses of land, 



Jt has been remarked by Dr. Lloyd that * Ireland, 

 ituated as it is at the north extremity of Europe, and 

 exposed to the full influence of the northern branch of 

 the gulf-stream which sweeps its western shores, has its 

 temperature as high as countries on the southern shores 

 of the Euxine." But it must be also considered, when 

 reasoning on this subject, that the same causes which 

 influence the high winter temperature operate in lower- 

 ing that of the summer. Owing to the great amount of 

 exhalations which take place, and the western winds 

 crowing over part of the Atlantic Ocean, which prevail 

 daring the summer and autumnal months, we have 

 generally cool, cloudy summers, which tend to lower 

 the average mean temperature of the year. In Ireland, 

 where those^ fine evergreen plants flourish so lux- 

 uriantly, it is not higher than in countries where 

 there is some difficulty in preserving them during 

 winter in conservatories, whilst, on the other hand, 

 plants in those countries are much influenced by the 

 greater summer heats which they experience, and are 

 thereby enabled to ripen both their wood and fruit 

 better. By tracing the isothermal lines over the map 

 of Europe it will be found that the one which passes over 

 the province of Munster extends on through Konigs- 

 berg, in Prussia, over the Isthmus of Perekop, on to the 

 borders of the Caspian Sea, where Grapes and Peaches 

 are produced in full perfection, without artificial aid— 

 which is not the case in Ireland— but where many of 

 our hardy trees and shrubs will not survive the intense 

 froete which occur during the winter months in those 

 locanues. It is thus clear that tender plants owe their 

 existence in Ireland principally to the mildness of the ! 

 temperature during the winter months, and not to the 



eponding months of the year 1851, as given by Dr 

 Lloyd, for the locality of Dublin. In his table showing 

 the mean temperature of each month of the year at the 

 several registering stations through Ireland, Dublin is 

 marked for January, 43.3; February, 43.6 ; December, 

 43.3 ; which indicate a more than ordinary mild winter, 

 since according to my calculations, taken from the 

 readings of the thermometers at the Botanic Garden, 

 registered once during 24 hours, the average mean tem- 

 perature of the month of December, 1854, is 42°, and 

 that of January, 1855, 40°, being rather under than 

 over those of 1851. Those differences may, however, 

 be owing, m some degree, to several readings having 

 been taken in the one case during 24 hours, and only 

 once in the other, as well as to the situations where the 

 instruments were placed, the Botanic Garden being 

 65 feet above the level of the sea, and freely exposed, 

 whereas the College is less than 10 feet, and, no doubt, 

 influenced by the heat of the city. A very marked 

 difference, however, occurs in February, the mean of 

 that month having been 41.7 in 1851, whereas, in 

 February, 1855, it was only 32 Q at the Botanic Garden, 

 which I believe is the lowest on record ; besides, the 

 minimum thermometer fell to 2° above zero, indicating 

 30 of frost on the night of the 1 5th, and, again, on the 

 18th it fell to 5 # , and on the 19th to 10°, which alone 

 goes far to show the principal cause of so much destruc- 

 tion to our out- door plants ; but when considered in 

 connection with the state they were in at the time these 

 frosts occurred, and the severity of the weather during 

 the present month, when they were recovering, fully 

 accounts for all the damage. 



On the 6th inst., the thermometer marked 8° of frost 





mter«t to ^those who are contemplating uew arrange- 

 ments, and who possibly may not have seriously studied 

 the matter. 



I may, therefore, premise that in 1843-4 I ws 

 entrusted with the re-arrangement of some old forcing 

 houses and pits, to which were added a considerable 

 extent of new erections. At that time Penn's system 

 of heating was much in fashion, and being much interested 

 m the matter and intimately acquainted with Mr. Penn, 

 1 was induced to adopt the * one boiler" system. The 

 plan was for nine distinct pits and houses, and to supply 

 both top and bottom heat to seven of them. The quan- 

 tity of pipe employed was very considerable ; indeed, 

 power sufficient was provided to heat the whole of the 

 houses properly with the thermometer 5° below zero, 

 and a piercing north-east wind. One of « Hill's flue 

 boilers" was employed (a better never had water put in 

 it), and such a quantity of brass stop valves (costing, I 

 think, about 42s. each), as makes me, now when I think 

 of it, blush at the expense. The draught of the boiler 

 was so good that it would burn anything and everything 

 that was put under it ; neither was the consumption of 

 fuel large for the work done, while of ashes not a 

 handful was taken out of the stoke hole in twelve months, 

 the only residue of the fire being clinkers. This boiler 

 for the thorough consumption of fuel and for the 

 prevention of the loss of heat un the 



generally a great source of loss though 

 observed, was the best I ever worked. 



chimney, 

 but little 

 Hence the 



arrangement, so far as the engineer was concerned, was 

 in every respect complete. But how did it work ? 



The greater part of the glass was employed for forcing 

 purposes, such as the growth of Pines, Melons, Cucum- 

 bers, stove plants, &c, and nearly 400 feet of pipe was 

 employed to heat a large span-roofed greenhouse. The 

 heating was complete, the attention to the fire was of 

 course that of one instead of four or five, but as 



7M^ next day ; and on the 25th! regards the valves to regulate the temperature of the 



LSA^ vari ° u ? houses, how worked they? In one place we 





frosty winds which prevailed during the month, circum- 

 stances which have been very injurious to plants in 

 their present condition. 



I have already stated that I could not get any reliable 

 registerings of the thermometer, indicative of the state 

 of the weather during the early part of the present 

 century ; but Mr. Yeates has kindly furnished me with 

 notes of the lowest points to which his thermometer fell 

 during the last 12 years, from which I find it did not 

 mark lower than 10° above zero during that period. I 

 learn also, from the same data, that the greatest colds 

 during those years occurred between the 6th to the 18th 

 February, though in some instances in January. 



Before passing from this part of the subject there is 



Mm temperature of the year, which only averages 

 m Fahrenheit ; m 1851 it averaged 50 », according to 



Wr. Lloyd. Bv referring *« *k~ u: u\ • ± ?• *T~ r— "— *e **y*« tmopaibui uic sumec* mere la 



tables prepared* bv £ Zt\L™\X?l uteres ,ng one other meteorological circumstance I shall briefly 



* the « f reactions o ttn^ d ^ly publ.shed notice, because I consider that many of our herbaceous 



■ lraDsa <*">ns of the Roval Irish AcarWrw" as well as w00 dy plants owe their partial safety to it 



Ireland. 



i» «m v. rraD8a , ct,on8 of the Royal Irish Academy, 

 « wll be seen that the most important climatological 

 £«, which are observed on a large scale through sea- 

 ward and mland counties over Europe, hold good in 



On this head Dr. Lloyd observes, that, upon 

 comparison of the mean yearly temperatures of the 

 «w»M stations where meteorological observations were 

 wae, it has been found that those of the inland stations 

 «ew delect, as compared with the corresponding 

 ww stations— e. g., the mean temperature of Armagh 



rt» ™« 'I l de S- than Donaghadee ; and, again, 

 2»»ean temperature of Markree-482-is less than 

 ««« Mlybegs, on the coast of Donegal, by 2.6°, and 



July th est P° rt .» on the co«.t of Mayo, by 3.5. Simi- 

 -n„kr u 18 . an increa se proceeding from east to west 

 north tl i ng u 4 ? iO ' and W <*tport, 5.1.7 ; and from 

 49° »„2 T^' bem 8 at Portrush, on the Antrim coast, 





-48.6 



i 



Faare] 



Mil 



relativ 



Ion 



namely, the unusually small fall of rain which 

 occurred during the autumnal winter months. By 

 referring to the meteorological tables published lately 

 in the proceedings of this Society, it will be found 

 that only 10£ inches of rain fell from the 1st of July 

 to the 31st of December, which is below the average 

 quantity for that period in the neighbourhood of 

 Dublin, The ground was, consequently, drier than it 

 usually is in February ; and although the smaller 

 plants were snugly ensconced under a good covering of 

 snow — which was, no doubt, the principal protecting 

 medium— they would have suffered more had the ground 

 been saturated with moisture, as I find the same species 

 has been more affected in wet parts of the garden than 

 where the ground is drier. 



Having now considered, as briefly as I could, the 

 prevailing meteorological causes which affect plants in 

 Ireland, as well as those which have led to the 

 destruction of so many in the present instance, it will 

 have appeared that the moist equable temperature and 

 cloudy skies which we generally experience during the 

 autumnal months operate on them in two ways opposed 

 itfjiDffmvRPlf mn^^v^i x *u i* 1 :, to each other respecting their hardiness. Under these 



ififtm! Thai T* r ^Vi * 6 SU u je . Ct Unde L r fa ™r abl * c^atal influences they often continue to 



1 have not been *hl- ♦„ .u, n -^ grow iuxuriantlv up t0 Christmas, when their wood is 



soft and unable to resist frosts so well as it would be 

 if the autumnal months were clearer and warmer to 



> 



h*! Dromore > on ^e coast of Waterford, 51- 

 teieh tk! ' W • are im P°rtant data in aiding us to 

 tfecld ; prox . ltnate cau * e s of plants being differently 



*hen h*? r Van0U f parts of Ireland > and will, no doubt 



**** To/ z Tl 00 u^ ca!ieris * aribus ~ 8° far t0 



coaatry. attribution of some species in this 



lilt 



8 durati 



in* - not been ab,e to obtain mnch 



miormation which could be depended on, to 



wnat previous periods any very intense frosts of 



ion occurred in Ireland. It is said that the 



ripen it properly, and the early winter months suffi- 

 ciently cold to arrest growth. Now, this is what takes 

 place in those countries on the continent of Europe 

 whose annual mean temperature equals that of Ireland, 

 and also in several parts of England and Scotland the 

 seasons are more marked, which accounts for the 



-v iu me same **^t>* #k^, u« I *u- ' "ITVI superior ripening of fruits, as well as the comparative 



*y **,t resulted ^ hoTlh^i^T ^ **"' * hlch hardiness of some plan4 ; take, for example, the 

 thewi^ _. 8ulted from the cold happening earher in average mean temperature of the month of August, as 



that of 



*top-rati,;r i ^ urrea ln Ireland. It is said that the 



1***- hZ*u n0t been 80 low durin S the laj * 40 

 ^PPeiionia ?f em T aybe SOme ^take in this ; my own 



* 1831 it !u . w the ther ra<>meter as low as zero 



* 8«ow 11 ^ ull J 8ide of the ^ty, when a greater fall 

 plants suZ ? i an we have latel ? experienced ; 

 ^riy tft fiL Ver ? much in consequence, though not 

 ^ / io the same »^ n r *k^« ^% Ye thir - -*-- ' 



happening earlier in 



^**biv"ihl" Ca mey Were in a more dorraan t state, or, 

 pcevions* ant * WOOd had been better ri P ened ^ring the 

 ^Und th D i thereb y rendering them abler to 



^MipnM,^ 0f the fr08t - This )' ea r they 

 0f *dteabm! y t0 be iu 'i ured y owi *g t0 the state 



rem **kablv m L ID&ny ° f tbem were iD > arisin g f rom the 

 *** of N weathe r which had prevailed during the 



{^hadjou^K 6 ^ December > and January. The 

 ^& *nd w*°* • 00t8 » on 80me of them several inches 

 *** in a stat 6 m r ful1 leaf > and other out -door plants 

 ^f^ of the se unnatural forwardness at that early 



^*ree m^u U ' Scarcel y any frost occurred during 

 ** ^Tine f a , u« i t0 arrest ve getation, the thermometer 



*tb*io g ; a J ,en lower than tn 9ft<» ok„,~ „~.~ ;„^; 



it occurs in Hungary, and compare it with 

 Dublin, under the same isothermal line ; in the former 

 it is 69.8, and in the latter only 60 deg. ; but in Novem- 

 ber the scale changes conversely at nearly the same 



ratio* ( To he concluded in our next.) 





ARE LARGE BOILERS ECONOMICAL ? 



." ~«*"ig nover 

 December it also 



the 



above zero, indi- 



r on 

 ght, 



period the temperature of the 



Without in the slightest degree wishing to disparage 

 the arrangements which Messrs. Weeks and Co. have 

 made for heating their plant houses, &c, and which 

 you have described at p. 807 of the last volume of the 

 Chronicle, I may perhaps be permitted to ask the pre- 

 ceding question ; and as I speak from experience, and 

 have reason to doubt both the economy and policy of 



employing one boiler to do the work generally assigned 



to several separate and distinct arrangements, I imagine I ment be economical 1 

 my convictions on the subject may not be without need further explaua 



wanted a temperature of 75 p , in a second 70°, in a third 

 65°, a fourth 50° and so on, the greenhouse being filled 

 with hard- wooded plants merely requiring to have the frost 

 excluded. So long as the valves were properly attended 

 there was no difficulty in maintaining the temperature in 

 the different compartments, but as the heat required shift- 

 ing from one place to another, being one hour here, two 

 hours there, and three hours in another place, the 

 attention required was continuous, and hence, in the 

 height of the forcing season, especially if the weather 

 was severe, it was impossible, either day or night, to 

 leave the valves for more than two or three hours 

 together. And this was not the worst of it, for possibly 

 just as the forcing department was got into proper con- 

 dition to leave for the night, down went the thermometer 

 in the greenhouse, and the heat must be turned on. 

 Then rather than cool the water in the forcing depart- 

 ment, it was stopped off at the boiler, and the poor 

 attendant had not only to wait until the greenhouse was 

 sufficiently warm to leave with safety, but he must also 

 dance attendance until the forcing-pits were at the 

 required temperature, and thus it may be fairly in- 

 ferred that the heating of the greenhouse, in addition 

 to the forcing-pits, required more attention from the 

 stoker than would have been necessary had a separate 

 boiler been employed to heat that one house. 



lam, therefore, quite convinced that in point of labour 

 and attention a single boiler involves more attention, 

 and is far more difficult to manage, so far as accuracy 

 of temperature is concerned, than if several separate 

 boilers were employed. 



Again, as to the expense of working and consumption 

 of fuel — and here I may as well once more dispel the 

 mystery in which this subject is involved. A given quan- 

 tity of fuel contains a certain amount of caloric or heat. 

 Now, that boiler which the most effectually absorbs or 

 abstracts the caloric or product of combustion with the 

 least loss by the furnace doors or up the chimney is 

 the best ; and it matters not what its form may be, 

 whether square, circular, conical, flue, saddle, or tubular, 

 so long as that object is attained. A given quantity 

 of water requires a certain quantity of fuel to heat it, 

 and it is a matter of very little importance whether one 

 boiler or half a dozen be used so long as the caloric or 

 heat is completely abstracted ; the loss, if any, will be by 

 the heating of the additional masonry of the six boilers 

 and the five extra chimneys, but unless there is full 

 work for the large boiler at all times, I am convinced 

 that the loss by the additional masonry will be more 

 than counterbalanced by the saving in only using the 

 small boilers for such work as may be necessary in the 

 summer season. As an example of the successful 

 working of Mr. Weeks's arrangement, we are told that 

 a small pit situated 365 feet from the boiler was raised 

 60° of temperature in a very short time, and for the 

 purpose of testing the economy of large boilers, we 

 will just examine this fact a little further. It is quite 

 certain that in Mr. Weeks's case he does not, except in 

 severe weather, require to use heat for more than 

 one-third of his glass ; in the summer not more than 

 two or three houses require artificial warmth ; and it is 

 just possible that in a private establishment only this 

 single pit for several months in the year might require 

 to be heated. Allowing such, then, to be the fact, it is 

 quite certain that the large boiler and the water con- 

 tained in 730 feet of useless pipe must be heated to do 

 the work which, under a separate arrangement, would 

 be equally well accomplished by comparatively a tea- 

 kettle and a handful of coals. Can such an arrange- 



The answer is too ^elf-evident to 



may be argued that 



