Braid Styles of the 1850s (and 1880s): Basket Plaits

The third fancy plait from The Englishwoman's Domestic Magazine (1856) / Sylvia's Book of the Toilet (1881), is the basket or chain plait.  It's basically the standard three-strand plait, with a fourth strand running straight through the middle, which the other three wrap around.

Step 1: Divide the hair into four sections.

Step 2: Take the right-most section and bring it over the nearest section, then under the next and over the last.  The formerly-right-most section of hair should end up as the new left-most section.

Step 3: Take the second-left-most section and take it over its right neighbor, then under the far right section, making it the new far-right section.

Step 4: Take the second-right-most section over the mid-left and under the far-left sections.

Step 5: Repeat steps 3 and 4 until the desired length is reached.

And voila:

This one definitely makes more sense with all four strands differentiated, so here it is in multi-colored yarn.  As before, orange starts on the far left, pink in the middle, and purple on the far right; the new white thread begins in the left-center position (pink in right-center), and so will never move.  It will stay in the middle while the other three strands braid around it.

The four strands.

Purple goes under pink, over white, under orange.

Orange having already gone "over" purple as it worked across, continues
under the white and over the pink, to its new far-right position.

Pink already having gone under orange,
continues over white and under purple.

Continue picking up the last thread crossed and taking it back the
other way; under/over/under or over/under/over, depending on the
last move.

Left open, you can see the orange, pink and purple strands making
a basic three-strand braid.  The white strand stays in the middle,
but weaving in and out of the three-plait.

Braid drawn tight.

Here's the basket plait with a regular three-strand braid braid crossing it.  The fourth strand makes it look more elaborate and "woven" than with three alone, but it's not difficult once you get started.