Cut off ends of oranges. Thinly slice the oranges (keep the peel ON), then cut each slice into 4 pieces. Place oranges, water, and ½ cup fresh lemon juice in a large stockpot (6-8 quart). Bring the mixture to a boil on high heat, then reduce heat and simmer, uncovered for one hour (or until peel is tender),stirring occasionally. Measure out EXACTLY 7 cups of the cooked orange mixture. If necessary, add water to make 7 cups.

Prepare water bath canner (filled half way with water), canning jars and lids according to manufacturer instructions and general canning guidelines. Bring water in canner to a simmer.

Measure out the granulated sugar into a large bowl and set aside until ready to add to jam.

Place 7 cups of prepared orange mixture in large stockpot. Add box of Pectin and stir to combine. Bring mixture to a rolling boil on high heat (a rolling boil is when it's boiling so hard it won't stop bubbling even when stirred).

Ladle marmalade into hot, prepared jars. Fill the jars, leaving ⅛ inch headspace at the top. Remove air bubbles with a plastic utensil. Adjust the headspace, if necessary, by adding or removing jam.

Use a damp cloth or paper towel to wipe down rim and edges of the jar. You need it free of debris in order to get a good seal. Cover with a hot, flat jar lid. Screw on bands to fingertip tightness.

Lower the jars on an elevated rack into the simmering water in the canner. The jars must be completely covered with water, and have at least an inch of water over the top of the jar. Add more boiling water to canner, if necessary. Cover the canner; bring to a gentle boil. Once water is boiling, process jars for 10 minutes. When done, turn off heat, wait for a minute, carefully remove canner lid (lift lid away from you because of steam); lift each jar out (with canning tongs), and place on dish towel on counter to cool (don't put jars directly on counter because temperature differences could possibly crack jars). You should hear "ping" sound as the jars seal properly.

After the jars cool off, you can check to see if jars sealed properly by pressing the middle of the lid. The jar should NOT spring back when touched. If it does spring back, the jar did not seal properly for long term storage, so you will need to refrigerate that particular jar. Let the sealed jars stand at room temp for 24 hours, wipe clean, label, then store unopened in a cool, dark place.