APPENDIX. 



755 



1 cubic foot of Marble weighs 

 „ Chalk, 

 ,, Basalt, 



Limestone, 



Oak, 



Box, 



Yew, 



Ash, 

 ,, Beech, 

 ,, Walnut, 

 „ Elm, 

 ,, Larch, 

 ,, Poplar, 



Cork, 



1 cwt. of Cast-iron contains, 

 ,, Bar-iron, 

 , , Cast-brass, 

 ,, Cast-copper, 

 ,, Cast-lead, . 



lb. 



. 171* 

 . 174 

 . 179 

 . 198f 

 from 54 to 73 

 . 57 

 50h 



. m 



43A 

 . 43 

 34| 

 34 

 24 

 15 



Cubic 

 inches. 



TABLE OF THE SPECIFIC GRAVITY OF A FEW MATE- 

 RIALS USED IN HORTICULTURE. 



Of Rain-water, (distilled water being 



430.25 

 397.60 

 368.88 

 352.41 

 272.8 



126 gallons of rain are calculated by Waistell to 

 fall on every square yard annually in Britain, or 

 2722^ tons per imperial acre. Other authorities 

 say, taking the annual fall of rain at 31 inches, it 

 would give 3100 tons per acre. 



The constituents of our natural atmosphere 

 are nitrogen, oxygen, aqueous matter, and car- 

 bonic acid, in the following proportions : — In 

 ] 00 parts of 



77.50, or by measure, 77.55 

 21.0 „ „ 23.32 

 1.42 „ „ 1.03 

 0.8 „ „ 0.10 



Nitrogen, by weight, 

 Oxygen, „ 

 Aqueous matter, , , 

 Carbonic acid, ,, 



The mean force of the wind during the year 

 has been computed to be at 9 a.m. 0.855, at 3 

 p.m. 1.107, and at 9 p.m. 0.605, showing a greater 

 force during the day— no doubt to be accounted 

 for from the difference of temperature between 

 day and night. 



Temperature sinks about 1° Fahr. for every 

 352 feet of elevation ; but this varies a little 

 with the season, and very considerably with 

 the latitude. The above is near the proportion 

 in the temperate zones. 



Woods- 



taken as 1.000,) 





1.0013 



Sea water, 





1.027 



Common earth, 





1.48 



Rough sand, 

 Earth and gravel, 





1.92 





2.02 



Moist sand, 





2.05 



Clay, . . . 





2.15 



Clay and gravel, . 





2.48 



Lime unslaked, 





1.842 



Basalt whinstone, 



2.8 



to 3.1 



Granite, 



2.5 



to 2.66 



Limestone, . 



2.6 



4 to 2.72 



Stones for building 



1.6 



6 to 2.62 



Brick, . 



1.41 to 1.86 



Iron-wrought, 



7.207 to 7.788 



Lead flattened, 





. 11.388 



Rock salt, 





2.257 



— Alder, fresh felled 



0.8791 



Dry, 0.5001 



Ash, 



0.9036 



„ 0.6440 



Aspen, . 



0.7654 



„ 0.4302 



Birch, . 



0.9012 



„ 0.6274 



Elm, 



0.9476 



„ 0.5474 



Horse chestnut, 



0.8614 



„ 0.5749 



Larch, . 



0.9206 



„ 0.4735 



Lime, 



0.8170 



„ 0.4390 



Oak, 



1.0754 



„ 0.7075 



Spruce, . 



0.8699 



„ 0.4716 



Scots fir, 



0.9121 



„ 0.5502 



Poplar, Italian, 

 Willow, 



0.7634 



„ 0.3931 



0.7155 



„ 0.5289 



— Peschel's Elements of Physics, vol. i. p. 151, 187. 



Table showing the Number of Plants required to Plant an 

 Acre, Scotch or Imperial Statute Measure, from One 

 Foot to Thirty Feet distance, plant from plant. 



Dis- 



Scotch 



1 



Imperial 



Dis- 



Scotch 



Imperial 



tance. 



acre. 



acre. 



tance. 



acre. 



acre. 



Feet. 







Feet. 







1 



54,760 



43,560 



8 



855 



680 



2 



24,387 



19,360 



8§ 



758 



602 



13,690 



10,890 



9 



676 



537 



OJ- 



8,761 



6,969 



10 



547 



435 



3 2 



6,084 



4,840 



12 



380 



302 



H 



4,470 



3,556 



14 



279 



222 



4 



3.422 



2.722 



16 



213 



169 



4£ 

 5 



2,704 



2,151 



18 



169 



134 



2,190 



1,742 



20 



136 



10 



5^ 



1,810 



1,440 



22 



113 



90 





1,521 



1,210 



24 



95 



75 



6* 



1,296 



1,031 



26 



80 



64 



7 



1,117 



884 



28 



69 



55 



n 



973 



774 



30 



60 



48 



