I think this must be a Jewel, produced as a badge motor by this well established electrical company to make the most of the new detachable motor "fad". It's included here because the article in a 1915 Rudder issue which named the major brands of the time listed Ashbrook Electric.

Ashbrook Electric Co. made storage batteries and accessories for marine use. They sold the Jewel in 1915, by the way...and the photo here is the same as that ad.

My research is limited primarily to online sources so they may have advertised much more in a series of magazines that are not available to me. Note this ad is from 1918 and the Rudder listed the company in 1915.

Below is a 1915 ad before Jewel produced a badge motor for Ashbrook.

Text of the above 1918 ad reads:
Ashbrook Marine Specialties

The line of Electric Specialties we make for Marine use
will surely interest you.
We want reliable agents. Write us for agent's proposition.

Electric Row Boat Motor —Write for details of the Ashbrook Detachable Electric Row Boat Motor. Run by Storage
Batteries. Powerful and smooth running. Change your
Row Boat into an electric launch in a moment.

Storage Batterles - We make the high-grade Ashbrook
Storage Batteries for marine use. Also storage batteries
for every line of industry. Ashbrook Batteries are reliable.
Marina Lighting Plants—Ashbrook Lighting
Plants for marine use are specially designed by
expert engineers who know what you require.
Motor Boat Specialties—Send five cents in
stamps for catalog describing any of the above
Ashbrook lines.

Attractive territory open for
reliable parties who write us at once.

Ashbrook Electric Co., 4117 Ravenwood Ave., Chicago, Ill.