Snail mail came through and delivered:

* \#25 sprocket with 3/4" bore and 45 teeth. This goes on the wheel axle.
* \#25 sprocket with 5/8" bore and 18 teeth. This goes on the differential axle, and this sprocket shares a chain with the wheel axle sprocket.
* \#25 sprocket with 5/8" bore and 24 teeth. This goes on the differential axle, and it shares a chain with the flywheel axle.

The first and third sprockets need to have keyways cut out. Joe at the machine shop in Emerson will help us tomorrow at 10am to [broach|https://www.youtube.com/watch?v=ZRbOux9NfeU] these keyways.

Reading:

* The [WaterRower|http://www.waterrower.com/] is a rowing machine that uses liquid water and a spinning paddle as the drag mechanism. Its performance monitors [incorrectly calculate distanc|http://freespace.virgin.net/neil.wallace2/waterrowergate.htm]e rowed by simply multiplying the linear displacement of the handle by 5. This means that a rower can increase perceived velocity by rushing the recovery and pulling faster rather than harder.

 !http://upload.wikimedia.org/wikipedia/commons/9/94/WaterRower_Rowing_Simulator.jpg|align=center,border=1,width=300!

* A rower's power is proportional to the cube of velocity: {latex} \large $P = v^3$ {latex}. For example, rowing at a 2:00 per 500m pace requires twice as much power compared to rowing at a 2:30 pace.