Martin Rocking Fifth Wheel Co. v. United States

The action is to recover certain excise taxes said to have been erroneously assessed, and involves in its determination the character of the subject matter of the tax called “ semitrailers.”

A trailer is a vehicle for the carrying of persons or property, chiefly the latter, which has no motive power of its own, but is moved by being attached by one method or another to another vehicle having propelling power or being horse drawn. The method of attachment may be said to be the distinguishing feature of the type of trailer here involved.

There are four-wheel trailers, which carry on their own…