<number id="speed" type="slider" arg="-speed %"
_label="Speed (of smallest disks)" _low-label="1" _high-label="20"
default="1" low="1" high="20"/>
+
+ <number id="trails" type="slider" arg="-trails %"
+ _label="Length of disk trails" _low-label="0" _high-label="10"
+ default="2" low="0" high="10"/>
<boolean id="fog" _label="Enable fog" arg-set="-fog"/>