HORTICULTURAL APPLIANCES AT THE PARIS EXPOSITION. 



A TRANSLATION OF CH. JOLY's "RAPPORT SHR LES SERRES LE MATERIEL DE l'HORTICULTURE. ' 



[Concluded from page 



HE HEATERS for our hot-houses 

 were at first in the form of a 

 horse-shoe, and only utilized a 

 small amount of the fuel. I 

 shall only mention the brick fur- 

 naces still found in Belgium. 

 These had pipes made of pottery 

 resting upon the soil. They are 

 cheap arrangements and have many inconveniences. 



For our greenhouses the object is not, as in manufac- 

 tories, to obtain a high temperature, for water boils at 

 212°, and this heat must be avoided. What is needed 

 is to be able to utilize fuel with simple appliances 

 which shall be economical, and easily examined and 

 cleaned. For this purpose numerous inventions have 

 been made, all having in view an increase of the heat- 

 ing surface. They can all be reduced to two principal 

 systems : Those with boilers having vertical tubes and 

 those with horizontal ones, and perhaps, also, those 

 in which the plates are more or less multiplied. Some- 

 times the boiler is placed under the greenhouse itself, 

 and this has many advantages if one does not consider 

 the cost ; sometimes it is placed below and outside, 

 under shelter, at one of the extremities of the house, 

 the surface of the boiler itself furnishing heat as well as 

 the pipes. The doors of the fire-box and the smoke- 

 pipe are outside to avoid the dust ; sometimes, when the 

 soil is moist, or if one wishes to avoid expense, the boiler 

 is placed on the ground of the greenhouse itself, but 

 care must be taken to place the -expansion tank and the 

 pipe for the escape of steam upwards. Many builders 

 have studied this subject in particular and understand 

 better the scientific conditions of good heating, com- 

 bined with solidity and durability of the apparatus. 

 They are right in insisting upon the utility — 



(1) Of having in all large establishments an extra 

 heater for extreme cold, or to replace the one in use if 

 it should need repairs. 



(2) Of having more pipes than are strictly necessary, 

 in order to avoid over-heating the immediate surround- 

 ings of the pipes. 



One has often proposed tests in which there should 

 be either a series of greenhouses having the same 

 dimensions, exposure, etc., etc., or a certain number of 

 reservoirs of equal capacities, placed in conditions 

 equal in respect to distance and loss of heat. In gen- 

 eral, these tests, where one has used the same fuel and 

 employed the same instruments for observation, have 

 not given the results which were expected, for besides 

 simply the heatmg, one must consider the conditions of 



y^J, Dei eijibey issue. ) 



price, solidity, simplicity, durability, ease of cleaning, 

 rapidity in heating, etc. 



The heaters commonly used now are much the same 

 as those used in manufactories. They consist of a fire- 

 box surmounted by pipes of various diameters, to in- 

 crease the surface for heating. In the center there is a 

 reservoir for the fuel, which slowly feeds the fire in 

 proportion to the combustion. As to horizontal heat- 

 ers, they are surmounted by plates, between which the 

 burnt gases circulate, or by layers of tubes. The cop- 

 pers of commerce being usually costly and impure, 

 riveted sheet-iron, or even castings, are usually preferred. 



In general, our manufacturers have progressed since 

 1878, and now build durable heaters which are easily 

 managed. 



GREENHOUSES, KIOSQUES AND RUSTIC CONSTRUCTIONS. 



At the beginning of this report I said that the Exhi- 

 bition did not possess one greenhouse in which large 

 plants might have been grown. Moreover, the twenty- 

 five greenhouses scattered about the Trocadero were in 

 no way remarkable. The central part of each was 

 elevated for large plants, and there were usually two 

 wings, one for the cold house and the other for the 

 temperate house. It would have been excellent to have 

 had a large structure for a winter garden, in order to 

 compare the work of our manufacturers with the ex- 

 pensive structure of Rome, which has spent so much on 

 its museum with such little effect — and this will always be 

 the result when ordinary architects are employed, for 

 these consider the needs of horticulture as of minor 

 importance. 



The building of a greenhouse is, from a horticultural 

 standpoint, a very important matter, for it includes 

 glazing, shading and especially heating. Since it has 

 became known that ordinary builders of greenhouses, 

 and particularly architects, understand nothing what- 

 ever about their construction, and especially of the 

 needs of plants, a new class of builders has arisen. 

 These use iron, mainly, and not only build greenhouses 

 at reasonable prices, but also winter gardens and con- 

 servatories for houses. As for the botanists and 

 amateurs who wish to grow all the plants of the world 

 in one place, they know that, in order to succeed, one 

 must furnish the same conditions of soil, light, heat 

 and moisture as the plants had in their native regions ; 

 hence the necessity of structures of different dimensions, 

 arranged so that they are united by corridors containing 

 the return pipes. The above arrangements are for 

 large establishments. The conditions required for 

 ordinary greenhouses are as follows : 



