54 



JOUENAIi OF HOETICULTUBE AND COTTAGE GAEDENEE. 



[ Jonuaiy 18, 187a 



any object, either natural or artificial, that may stand upon or 

 be included in it, such as an ornamental tree, a statue, a piece 

 of water, or a hillock. 



To do BO correctly it is necessary to have a cross staff. A 

 cross staff can be made in the following maimer : — Take a 

 piece of board 6 inches square, and cut two grooves in it at 

 right angles, as A, b, c, T>,fig. 51 ; fix a circular iron plate, as 

 E, to the under side of the board by means of three screws. 

 The circular iron plate has a tube attached to it. The tube is 

 dropped on to staff F, and fastened by means of screw g. It 

 is also necessary to have some station staffs 5 or 6 feet long, 

 and a measuring tape. 



The means employed for finding the dimensions of the 

 piece of ground in 

 /iff. 52 win be suffi- 

 cient to illustrate the 

 manner in which to 

 survey accurately any 

 piece of land for 

 general use. 



Fig. 52 is an irre- 

 gular piece of ground, 

 the outline of which 

 is required, and also 

 the exact position of 

 the circles included 

 therein, and tire space 

 they occupy. Insert 

 a station staff at each 

 angle, as at a, e, c, d. 

 Prom A to E is a 

 straight line 57 feet 

 long. Let the assist- 

 ant take one end of the 

 tape, and also some 

 pegs 12 or 14 inches 

 long. Let him start 

 from station b, taking 

 care to keep in the 

 straight Une between 

 stations B and c. At 

 the distance of 13 feet 

 6 inches from station 

 E insert a peg. At 

 that point there is an 

 offset of 1 foot. At 

 this point it will be 

 seen that it is neces- 

 sary to find the exact 

 position of circle a. 

 Take up the peg at 

 13 feet 6 inches, and 

 set the cross staff 

 in its place ; look 

 through each end of 

 the groove running 

 in the line E c, as, 

 for example, groove 

 A B in fg. 51 ; if sta- 

 tions B and c are seen 

 through the groove, 

 the cross staff is in 

 the right position to 

 erect a perpendicular. 

 Look through groove 

 c D in the direction of 

 the object, as in circle 

 a. Send the assist- 

 ant with a staff,: and 



direct him to put it into the proper place (as near the object as 

 it is necessary or expedient) ; measure the distance from staff to 

 staff, which in this instance is 9 feet" 4 inches, at a right angle 

 with line e c. Find the square of the circle, as hereafter ex- 

 plained, in eh-cle c. Let the assistant take the end of the tape 

 and go towards station c, keeping in the straight line between 

 the two stations e, c. At a distance of 33 feet from the point 

 where the staff is inserted at 13 feet 6 inches from station e, 

 on line B c, measure the offset, as at point 3, which is done by 

 placing the cross staff at the point on hne e c, taldug the 

 sight of stations b and c as before described. Look through 

 the other gi'oove, and direct the assistant to place a staff on 

 the boundary line, as at point 3. Measure the distance from 



BSyfoeC- 



Scale 24 feet to the inch. 



staff to staff, which is 3 feet. From the staff at point 33, on 

 line E c, measure 17 feet, this being the spot at which the 

 boundary line diverges most from the visual Hue b c, and 

 measure the distance of the set-off as before described, which 

 will be found to be 4 feet. Place the cross staff on line b c 

 (iu all cases observing for accuracy through groove a e the 

 stations e c) in a position that the Une seen through groove 

 c D shall cut the centre of circle c, as at point d. The dis- 

 tance required on line b c, from point 17, is 7 feet. Place the 

 station staff at points 7 and d ; remove the staff at point d, 

 and place the cross staff in its stead. Look through groove 

 A B, obsers-ing point 7, and through groove c n. Direct the 

 assistant to place the staves at any points, as in « c, which, 

 will be parallel to line 

 B c; place the cross 

 staff at point / on line 

 e e, and thi-ough the 

 other groove erect i^ 

 perpendicular, as in 7i, 

 and insert a staff. 

 Place the cross staff 

 in g, aud in the same 

 manner erect a per- 

 pendicular as in k. 

 Place the cross staff 

 on one of the perpen- 

 diculars thus found, 

 as at m, observing 

 through groove A n 

 the points / ft; and 

 through groove c i> 

 direct the assistant 

 to place station staves 

 as in points .s, s, which 

 will be parallel to line 

 e e. The circle c is 

 thus enclosed in the 

 square / g n m, the 

 side of which is 8 feet, 

 being equal to the 

 diameter of the circle. 

 The distance between 

 point 7 on line e c 

 and point d is 24 feet. 

 From the station staff 

 at point 7, on line 

 B c, measure 16 feet 

 6 inches ; place the 

 cross staff and mea- 

 sure the offset, which 

 is 2 feet, as before de- 

 scribed. From the 

 staff at point 16 feet 

 6 inches measure 

 13 feet 6 inches, and 

 measure the offset 

 (1 foot). Find the 

 circle o as described 

 in circle c. From the 

 staff at point 13 feet 

 6 inches to the staff 

 at angle c is 22 feet 

 6 inches, making the 

 total length of the 

 visual line E c 123 feet. 

 The points thus found 

 on the boundary line 

 (e 1 3 4 2 1 c) will be 

 sufficient to indicate 

 the curve of the line throughout. When the staves are removed 

 for the purpose of taking observations with the cross staff", 

 they must in all cases be replaced. 



Enter all measurements and observations in the note book 

 in the following manner, commencing at the bottom of the 

 page and working upwards. The page of the note book must 

 be divided into three columns, the middle column being used 

 to set down the distances from the starting point, as station B, 

 and also the distance of the point to be denoted from the 

 point last named, as shown in the annexed table. Commenc- 

 ing at the bottom hne — thus, e is the station point. The 

 first point at which an observation is made is at a distance 

 of 13 feet 6 inches from station B. The second point is 



