35i 



JODENAL OF HOKTICULTUKE AND COTTAGE GAEDENEE. 



[ May IS, 1871. 



temperature of London is within 1° of tliat of the Land's End, whilst 

 botli are about 10° warmer than the Shetland Islands. In December 

 and January, on the contrary, the temperature of London is within 

 1° of that of the Shetland Islands, whilst it is 5° colder than that of 

 the Land's End. In spring and autumn the lines occupy intermediate 

 positions, crossing the country in a diagonal direction ; but interesting 

 as it is to follow, in the successive monthly maps, the changes of 

 position of the lines, we cannot enter into farther description of their 

 changes here. The one broad result, as already indicated, appears to 

 be that, although during the summer warmth is to be reached princi- 

 pally by going south, in winter we soonest reach warmth by going in a 

 westerly or south-westerly direction. In the month of January, for 

 instance, it is rather warmer at Lancaster than in London, and several 

 degrees warmer in Wales. Apain, in the Isle of Skye, during the same 

 month, it is 2° warmer than at Aberdeen, and at the Land's End 

 6^ warmer than at Dover. 



A few remarks condensed from Mr. Buchan's discussion of his results 

 may be interesting. In referring to the powerful influence of the sea 

 in modifj'ing the courses of the isothermal lines in the different months 

 of the year, he alludes to the importance of making observations on 



the temperature of the sea also, and mentions that such observations 

 have for some years been made at different points round the Scottish 

 coast. One of the best illustrations of the inlluence of the ocean is the 

 high temperature of the northern islands during winter ; the conserv- 

 ing effect of the Irish Sea and English Channel may also- be traced. 

 The mildest winter climate of Great Britain is found in the peninsula^ 

 of Devon and Cornwall, a part of the country which as well as- beiug- 

 far south and west, is more completely enveloped by the ocean than anj^ 

 other. The climate of the British Islands is much milder in winter* 

 and cooler in summer than in continental regions in the same latitudes^ 

 the influence of the sea being everywhere felt. In those parts of the- 

 country, however, most removed from the sea the heat in summer i&- 

 relatively great. Thus, in London and the tract of country immediately, 

 to the westward of London, the temperature in summer is higher than, 

 that which prevails in the region around. Mr. Buchan discusses to- 

 some extent also the question of temperature in connection with agri- 

 culture and the maturing of crops, but we cannot here follow him 

 further, and must refer those who desire more information to the paper 

 itself, promising them that the maps alone will prove most interesting.- 

 subjects of study. — [3Ieduniics' Magazine.) 



GROUND LEVELLING AND PRACTICAL GARDEN PLOTTING.— No. 16. 



DRAWING PLANS. 



To draw and transfer to the ground fig. 39. Draw the reot- I are 6 and the other arcs having the radius o 6. 

 angle A b c d, also the diameter lines e f and o h. Draw lines | same peg, with a string 15 feet long, trace ate c 

 1 2, 3 4, 5 6, 7 



From centre o, with 

 radius o a, draw arc a; 

 with the same radius 

 draw all the arcs on 

 the circle a. With 

 radius o h draw arc h, 

 and all the arcs on the 

 circle h. From centre 

 draw ares c, d, and e, 

 also the centre circle o. 

 From point h, on line 

 A B, draw are /, meet- 

 ing lines I 2, 3 4 ; then 

 draw arcs g, h, and i. 

 From centre 9 draw 

 arcs r, s, and t. From 

 centre 10 draw arcs i, 

 m, and 7z. From centre 



11 draw are v, also 

 circle w. From centre 



12 draw are .r and 

 circle t(. From point 



13 draw are I and 

 circle p. Where the 

 lines cross each other 

 are the angles of the 

 beds. Draw the other 

 Bide in the same 

 manner. 



To transfer fig 39 to 

 the ground. From A to 

 B, which is the side of 

 the rectangle on which 

 this design is based, is 

 57 feet, and from e toe, 

 the other side, 83 feet. 

 Find points a, b, c, d ; 

 insert a stake at each 

 point, and lay lines 

 connecting them. Lay 

 diameter lines e f and 

 o H. On each side ot 

 the stake at point A 

 measure 2 feet 6 inches, 

 and insert a peg at 

 each point, as at 1 and 

 5. From stakes b, c, 

 and D find points 3, 6, 

 4, 8, and 2, 7 respect- 

 ively in the same man- 

 ner ; insert a peg at 

 each point. Lay lines 



connecting pegs 1 and 2, 3 and 4, 5 and 6, and 7 and 8. 

 a peg at centre o. From the peg at centre o, with a string 

 28 feet 6 inches lonj?, trace arc a, also the other arcs having 

 the same radius. Kaduee the string 2 feet 6 inches, and trace 



Fig. 39. Scale 16 feet to the inch. 

 Insert 



From the- 

 Eeduce the 

 string 2 feet 6 inches^ 

 and trace arc d ani 

 the other arcs having, 

 the same radius. From, 

 the same peg, with a- 

 string 5 feet 10 inches- 

 long, trace arc e. Be- 

 duee the string 2 feet- 

 6 inches and trace the 

 circle. From the stake 

 at point H, on line A E, 

 with a string 28 feet 

 6 inches long, trace- 

 arc /, as shown by 

 radius h f, meeting 

 lines 1 2, "3 4. Ee- 

 duce the string 2 feet- 

 6 inches and trace arc 

 g. From the same 

 point, with a string 

 15 feet long, trace arc- 

 h. Eeduce the string. 



2 feet 6 inches and- 

 trace arc i. On each- 

 side of centre o, on 

 line G H, measure 

 20 feet 9 inches ; in- 

 sert pegs as at point 13^ 

 With a string 8 feet 



3 inches long trace 

 are I. Eeduce the- 

 string 2 feet 6 inchea- 

 and trace circle p. 

 From the peg at point. 

 H, with a string 20 feet- 

 9 inches in length,, 

 trace an arc at point 9. 

 From the peg at point 

 13, with the same- 

 length of string, trace 

 another arc ; where 

 the tvro arcs cut each, 

 other is centre 9 ; in- 

 sert a peg at that point. 

 From the peg at point 

 9, with a string 10 feet 

 8 inches long, trace- 

 arc r, meeting lines 

 A B and A D. Eeduce 

 the string 2 feet 

 6 inches and trace arc- 

 s, meeting lines 1 i. 

 and 5 6. Again re- 



duce the string 2 feet 6 inches and trace arc «, meeting aros- 

 g and 7i. From the stake at point e measure 8 feet on line k t,. 

 and insert a peg as at point 11 ; from the peg at point 11, with 

 a string 8 feet long, trace arc v. Eeduce the string 2 feet- 



