550 



Simple Mode of taking the Height of Trees. 



or under cabbage leaves or haulm, and by soaking thoroughly 

 with lime-water the soil which he supposes to contain young 

 slugs or eggs.] 



Art. V. Notice of a simple Mode of taking the Height of Trees. 

 Communicated by J. B. W. 



Divide a square staff (« b^fg. 49.) of about 7 or 8 feet in length 

 into feet and inches, for the convenience of measuring the dis- 

 tance between the place of observation and the 

 tree, or taking any other dimensions. Upon one „ 



side of this staff, at a commodious distance from 

 the bottom, fix a rectangular board {c def) whose 

 length {d e) is exactly equal to twice its breadth 

 (c d) which breadth may be about 4 or 5 inches. 

 At c and d fix sights, or small iron pins, and also 

 aig and ^, making d g and g e each equal to c d. 

 Then, when the top of a tree is seen through 

 the sights at c and g, the tree's height is equal to 

 your distance from its bottom added to the height 

 of your eye; but if seen through the sights at c 

 and ^, its height is equal to twice your distance 

 from its bottom, adding the same height as be- 

 fore. In making an observation with this in- 

 strument, it ought to be fixed perpendicularly 

 to the horizon, which may be done by means 

 of a plummet suspended from n. In taking the 

 altitude of a tree growing upon an inclined plane, 

 you must endeavour to make your observations 

 from a place upon a level with the bottom of 

 the tree. If this cannot be done, direct the ho- 

 rizontal sights at c and d towards the lower part 

 of the tree, and let your assistant make a mark 

 upon it; then find the height of the tree above 

 this mark, as before, to which add the distance of 

 the mark from the ground, which must, in this 

 case, be considered the height of the eye, and 

 the sum will be the height of the tree. 

 June 10. 1841. 



Fig. 49. 

 Measuring Staff". 



Art. VI. Designs for laying out a Suburban Residence. By the 



Conductor. 



The situation for which the design fg. 50. is intended is near 

 Shepherd's Bush, and forms part of what was till lately an ex- 

 tensive brick field. The soil is a strong retentive clay, and its 



