TROTTING TRACKS. 191 



required for buildings. That, and the width of a track, 

 are matters for each association to decide for itself, and 

 will vary according to the uses to which the track is to 

 be put. For strictly a trotting association or county 

 fair ground, I think from ten to twelve acres about the 

 proper quantity. 



In the calculations and illustrations presented, dis- 

 tances are stated in feet, and (generally decimal) frac- 

 tions thereof. The illustrations will, I think, give any- 

 one a clear idea of how to lay out a track much better 

 than any written description can, if the ground be sus- 

 ceptible of having one built of regulation form. If not, 

 then special engineering is necessary. Special mention 

 need only be made of the methods for laying out turns, 

 as the stretches are simply matters of distances fully ex- 

 plained in the illustrations. There are three plans which 

 I regard the best to work by : 



The Engineer's Plan. 



For experts with approved instruments. For a regu- 

 lation mile track (see fig. i) ; From points of curve de- 

 flect angles of 3 degrees and lay off chords of 43-9& feet. 

 Ordinates from these chords (see detail fig. 4) at one- 

 fourth and one-half their length, are respectively 0.43 foot 

 and 0.58 foot. 



For a half-mile track (see fig. 3) ; From points of 

 curve deflect angles of 6 degrees and lay off chords 43.92 

 feet. Ordinates from these chords (see detail fig. 5) at 

 one-fourth and one-half their length, are respectively 0.86 

 foot and 1.15 feet. 



The Surveyor's Plan. 

 For surveyors with ordinary surveying implements. 

 The illustrations (see figs. 1 and 2) will clearly indicate 



