self-evident, so that I need not trouble you with further details in
this respect, but I would beg those who take an interest in the
progress of the electric locomotive to give this subject all the
consideration it deserves, and I would assure them that the system
which I have advocated in this brief but very incomplete sketch is
worthy of an extended trial, and ready for the purposes set forth.
There is no reason why those connected with electric lighting
interests in the various cities and towns should not give the matter
their special attention, as they are the best informed on electrical
engineering and already have a local control of the supply of current
needed for charging.

In the car which we use in Philadelphia there are actually 80 cells,
because there are considerable gradients to go over. Each cell weighs
40 pounds and the average horse power of each battery is six.
Sometimes we only use two horse power and sometimes, going up grades
of 5 per cent., we use as much as 12 horse power, but the average rate
is 6 electrical horse power. With reference to the weight of
passengers on the cars, we have never carried more than 50 passengers
on that car, because it is impossible to put more than 50 men into it.
There are seats for 24, and the rest have to stand on the platforms or
in the aisle.

The changing of the batteries takes three minutes with proper
appliances. One set of cells is drawn out by means of a small winch
and a freshly charged set is put in. It takes the same time to charge
the battery as it does to discharge it in the working of the cars, so
one reserve set would be sufficient to keep the car continually
moving.