  We investigated the velocity of an asymmetric camphor boat moving on aqueous
solutions with glycerol. The viscosity was controlled by using several
concentrations of glycerol into the solution. The velocity decreased with an
increase in the glycerol concentration. We proposed a phenomenological model,
and showed that the velocity decreased with an increase in the viscosity
according to power law. Our experimental result agreed with the one obtained
from our model. The results provided an approximation that the characteristic
decay length of the camphor concentration profile at the front of the boat was
sufficiently shorter than that at the rear of the boat, which was difficult to
measure directly.
