PARK AND CEMETERY. 
ROYAL BOTANIC GARDENS, KEW, SURREY, 
ENGLAND. VL 
PALM HOUSE. 
The curvilinear Palm House designed by Decimus 
Burton, was built in 1848. It cost, approximately, 
^30,000. Its central portion is 138 feet long and with 
each of the two wings 112^ feet constitute the entire 
length of the structure as 363 feet. The center is 100 
feet wide and 62 feet high, the wings 50 feet wide and 
26 feet in height. Ventilation is exclusively from the 
top by sliding sash (6 feet by 8 feet); these are mani- 
pulated by a crank and windlass. 
The walks in the wings are of cement. 
Temperature is maintained at 70 degrees and this re- 
quires eight large wrought iron tubular boilers con- 
nected with over 4 miles of 4 inch hot water pipe worked 
on the expansion system. The house is founded on a 
4 foot terrace. Supporting the house is a stone founda- 
tion rising 3 feet above the terrace level. Within, a 
3 y 2 foot stage encircles the house and ranged under- 
neath it throughout are ten hot water pipes. In each 
wing the floor for the huge tubs is of iron grating; un- 
derneath running longitudinally with the grating floor of 
the house 24 four inch pipes are disposed. In the large 
central dome are solid beds for planting out palms. In 
addition to the ten under each stage on both sides, fifty- 
four four inch pipes run under the grated walks longi- 
tudinally with the house. Walks vary in width from 4 
to 10 feet. One 3 inch pipe encircles the dome at a 
level of the gallery walk and two 3 inch pipes travel the 
length of each wing about 3 feet from the summit. 
Stoking requires but part of one man’s attention 
during the night. Nothing else but coke is burnt as 
fuel and that is conveyed to the boiler room, as are also 
the ashes removed, via: a long tunnel and four wheeled 
cars on tracks to and from a service yard. 
About 1,000 chaldrons of coke are annually burnt 
in heating this house. 
It is interesting to review experiences undergone in 
bringing about the successful management of this house. 
When first erected it was, we believe, the largest glass 
structure in existence and remained the largest in En- 
gland until the recently built conservatory of Sefton 
Park, Liverpool, was completed. To the engineers the 
problem was, how to utilize the least bulky and light 
obstructing material and maintain the necessary strength 
and durability; how to avoid currents of air and withal 
provide a perfect ventilation and further, to so distribute 
the heat as to preclude the necessity of subjecting the 
plants to an undue amount of dry air occasioned by the 
loss and radiation of heat. It was more or less experi- 
mental. Whether butted or lapped — the roof glass will 
usually show crevices, an item of considerable import 
in a house to be kept at 70 degrees. Previous to 1894 
but six boilers and less than 3^ miles of 4 inch pipes 
were used but since this has been increased by 10 addi- 
tional pipes running around the inside of the house and 
2 more boilers. 
True, the maximum cold will approximate only 20 
degrees Fahrenheit, and there occurs scarcely no wind 
T 45 
but even then the cubic contents of the house has a 
comparatively large exposure. In contrast we would 
mention the Phipps conservatories at Pittsburg. Here 
the main conservatory is quite low, and covers a large 
ground area, thus facilitating its heating and as in Lin- 
coln Park, Chicago, where cool plants are largely grown 
materially assisting their successful cultivation. 
In 1868 a renovation in the heating plant was ef- 
fected in the Kew Palm House reducing thereby the 
number of boilers from 12 to 9 and generating — as esti- 
mated by Sir Joseph Hooker — 10 per cent, more heat. 
Referring to. this house in 1869 report, Sir Joseph re- 
marks: “ ‘spray jets’ have been fixed to the roof, each 
of which disperse a misty shower of 12 feet diameter 
over the plants, which is in every way preferable to the 
old system of syringing” a decision that was on further 
experience reversed. Gratified with the first alteration 
tending toward the systematizing of heating apparatus 
Sir Joseph a second time — 1879 — advises that the old 
boilers be substituted by those of more modern manu- 
facture (those first used in this house were Sylvester’s 
“fluted conical.”) Heretofore the house was heated en- 
tirely from below but condensation in the dome was so 
rapid as to cause pools of water to collect on the gal- 
lery walks, and, more important, created a cool down- 
ward current from the dome and from the wings toward 
the dome. On this the then Director commits himself 
thus: ‘‘I feel satisfied that no plant house of any con- 
siderable height, whether built of wood or of iron, should 
be unprovided with a flow and return pipe at an eleva 
tion of at least half the height of the building both for 
the good of the plants and the preservation of the ma- 
terial used in construction.” 
Plants grown in this house are: the hotter palms and 
Dendrocalamuses, Zamias, Cycas, Dioons, Eucephalar- 
tos, Dombeyas, Kennedyas and on pillars and rafters 
many of the tropical climbers that have deciduous or 
thinly disposed foliage during the winter. 
Among the plants particularly noteworthy are: Sabal 
Black burniana, Phcenix farinifera, Macrozamia Hoper, 
Caryota furfuracea, Dioon Spinuloseun, Clorya mac- 
rophylla, Diplothemium candescens, Wallichiadensi- 
flora, Stevensonia grandiflora, etc. 
Six gardeners tend the house and patent adjustable 
ladders enable one to move in every part of the vast 
space within for cleaning, tieing, pruning, etc. 
Emil Mis c he. 
In England the first cost of making a highway is es- 
timated at $4,000 per mile; in France it is $6,000 and 
in Italy $,3000 per mile. The principal item of cost 
in England arises from the necessary purchase of prop- 
erty; in the mountain districts of France from the na- 
ture of the country through which the roads run. 
* * * 
There are two general systems of road making — the 
Macadam and the Telford. Macadam preferred a yield- 
ing foundation, and laid broken stone directly upon the 
earth; according to the Telford system, large blocks 
were placed as a foundation on which to lay smaller 
crushed stone with a covering of gravel, sand or ashes. 
