原文：
16.4. Is there a round Scale?
It is not quite a "round Scale" but Roy Johnson has written "Dial.pm" for round dial (or speedometer) -like settable widgets. It is available from: http://sun20.ccd.bnl.gov/~ptk/archive/ptk.1995.08/0431.htmlor http://www.perltk.org/contrib/etc/Dial.pm
As well as from the Contrib/ sub-directory of your perl/Tk build directory.
译文：
16.4. 有圆形的刻度尺吗？
没有完全的“圆形刻度尺”，但是Roy Johnson写了一个叫Dial.pm的模块，用来实现表盘（或计程表）式的组件。这个模块可以从下面的地址获得：
http://sun20.ccd.bnl.gov/~ptk/archive/ptk.1995.08/0431.html
或
http://www.perltk.org/contrib/etc/Dial.pm
也可以在你的Tk安装目录里的Contrib子目录中找到。（译者注：不过现在的版本中好像已经没有了……:-()。
