adapted from "The Old Farmer’s Almanac"
Break the eggs into a bowl and whisk them. Don't beat them and don't whisk them to a froth. Just make them smooth in the bowl. Because the eggs are the only rising material in the mixture, this maneuver is better underdone than overdone.
Then mix everything together well in a big container. As the mixture may be difficult to combine with a spoon, there is no objection to going in with your hands and really giving it a larruping.
This done, turn your attention to the pudding bag. Soak the cotton square in warm water and wring it relatively dry. Lay it flat on the kitchen table and flour the top side well. This will form a moist coating of flour on the cloth which is essential to removing the pudding from the bag later. Shake off excess flour.
Now dump the pudding mixture in the center of the cloth. The mixture will not be too "loose" and will remain pretty much upright in a blob. Gather the corners and edges of the cloth up around the mixture to form the "bag" around the pudding and tie off the pudding. Make allowance for some rising (the eggs) and some swelling during cooking. In short, don't tie the bag completely tight about the mixture, but leave a small emptiness between the string and the pudding. If you do it right, the ultimate pudding will have the form of a flattened orb, swelling to the precise size you have left in the bag. If you leave too much space, the pudding will sag.
Leave a loop in the string so you can thrust in the handle of a long wooden spoon to retrieve the finished pudding from the boiling water. Everything is going to be wicked hot when the time comes, and the loop is a must. Also, tie the knot around the bag so it can be easily untied.
Boil in a bag for one hour.
It is all right to add water during the cooking, but don't let the boiling stop at any time.