1. A new and original design for a manufacture.
2. An original design for a bust, statue, etc.
3. A new and original impression or ornament to be placed on any article of manufacture.
4. A new and useful pattern, print, or picture to be worked into or worked on, or printed, or painted, or cast, or otherwise fixed on any article of manufacture.
5. A new and original shape or configuration of any article of manufacture.
The first three of these classes would seem to refer to ornament only; the fourth to ornament, combined with utility, as in the case of trade marks; and the fifth to new shapes or forms of manufactured articles, which, for some reason, were preferable to those previously adopted.
The disputed questions which have thus far arisen under these definitions are:
1. What variations may be claimed or covered by the patent consistently with unity of design.
2. Is a new shape of an article of manufacture, whereby utility is secured, a subject of protection under this act; and
3. Is mechanical function of any kind covered by it.