very part. It is fascinating to see
the painters swinging in their chairs far up one of the cables or along
the strands that make the cobwebs at night. Every eight months a new
flooring has to be laid down on the driveway, and so you see there is
something going on constantly on the bridge that is worth watching.

I do not intend to tell anything about the bridge in the way of
statistics. The well-known facts as to length and height and cost and
power to resist strains may be found in any of the newspaper almanacs.
But there is one feature about the bridge that I do not think is well
known, and which has interested me greatly. I think it will be news to
most persons that up in the towers where the big cables rest there are a
series of steel rollers over which the cables pass. Each cable rests in
a sort of a cradle as it goes through the top of the towers, and under
each of these cradles are forty-three steel rollers, four and a half
feet long and three and one-half inches in diameter. It is well known
that the heat and cold elongate and contract the cables, and most of
those persons who know about these rollers think that they have been
placed there to allow the cables to lengthen or shorten themselves
according as the weather is hot or cold. They are in error on this
matter, however, for the rollers are placed in the towers merely to
equalize the strain on the bridge. The contraction and expansion are
equal on both sides of a tower, and so there would be no need of them on
that account.

If, however, there should be a great weight on one side of the bridge
and not on the other, then these rollers come into use. Under these
conditions the weight of the cables, and the structure they support, is
thrown down the inside of each tower straight to its foundations.

Another thing I like to watch about the bridge is the slip joint exactly
in the centre. There are two others of these joints, one between each
tower and the land anchorage, but the most interesting one is in the
centre. When a train of cars passes, you can see the joint expand and
contract three-eighths of an inch, and even when a carriage passes on
the roadway you can see it move a little. These slip joints are
necessary chiefly because of the heat and cold. In summer the cables are
fifteen inches longer between the towers than in the winter. The bridge
structure is cut in two in the middle, and an arm is fastened to one of
these ends. It slips into an opening