— 218 — 
SEPARATE RIVETS. 
No. 
Diameter 
Length under liead 
Kind of head 
Position in bridge 
Parts connected 
PIN PILOTS. 
No. 
External diameter 
Internal diameter 
Mark 
LOCK NUTS. 
No. 
Size 
Description 
Mark 
The following is the system of marking iron before shipment which the author 
would recommend. It should be tliorouglily comprehended by the mamifacture r f 
the foreman in charge of erection, anil tlie time-keeper or clerk, if there be eitli 0r 
employed on the work. 
"Where the work is very extensive, the time-keeper generally checks the mate^ 
ial as it arrives on tho ground. 
First, if there be more thau one span, each piece of each span should be marked 
with a daub of color peculiar to that span : thus the first span may be white, 你 0 
second yellow, the third blue, etc. ; care being taken to choose such colors fis will 
readily distiugui.slied upon the iron -work. 
The colors may bo marlied in the last column of eacli division in the il Shipps 
Bill M an(l afc the end: tlms the mark for a main diagonal may be " 3 B】”" 〇 1, “ 
W. ; n the fh.at representing the third set of main diagonals in the third span» 
the otlier the second set in the first span. The letters Bl. are chosen for blue， s0 
as not to be mistaken for tlie lotter B used elsewhere. A similar precaution sho u ^ 
be taken with tlie other colors. 
In addition to this characteristic color-mark, eacli piece should be marked ^ 
white paint according to the following method. 
R. and L. denote that the piece, if a main portion, lies to the right haud of 
the left hand when one stands at tlie nearest portal, astride the centre plane of ^ 
bridge, and looks tow irds the centre of tlie 
span. If a detail, it denotes that it lies to 
the right or left hand when one stands 
astndo the middle vertical plane of the 
truss to which the detail belongs, at the foot 
of tlie nearest batter brace, mul facing the 
centre of the span. Tlie numbers can be 「一 —— ^ —— -•.； ； 
readily understood by referring to the ac- I X t ノ * 七 /〆 レ 〆 {，ダ f 
comp an yin g diagram. 
Upper 
Lateral Systci» 
Truss 
Lower 
Lateral Syst^ra 
