of the pond up to fifteen inches of the top with large stones. Then in
between and over these put small stones so that you have filled in about
six to eight inches of the cavity. Now it is time to mix cement. Mix
only a little at a time. Get a board about two feet square. With a
trowel put on the board one part of Portland cement to three parts of
sand. Have a watering pot full of water at hand. Add water enough each
time to the cement and sand to make a soft but not running mass. If it
be possible for you to have small stones to put in, it will improve the
mortar you are mixing. These stones should not be larger than one inch
in size. Add four parts of these to the mixture.

Now over the bottom of the pond put on the paste about three inches
thick. Fill in with the trowel and smooth it off with the back of this
same tool. The sides are the next job. Put a board slantwise against the
bottom of the pond so there is a space between the board and the side
you are to plaster. Drop the mortar down into this space and press the
board against the sides. This firms the mortar. Keep up this work all
around the sides of the pond.

Another way to do this work is to make a box that will fit approximately
into the pond, but that gives a space all around over three inches from
the sides. Then the mortar may be dropped in. After three days knock out
the box and you have the inside all right. If you wet the sides and
bottom of the box the mortar will cling to it less.

If the mortar looks rather rough after you finish, mix cement with
water, take a whisk broom and with this brush the paste all over the
bottom and sides of the pond. All around the ground by the pond, mortar
for about six inches. This prevents the breaking in of the edges.