A loggerhead is a type of

tool A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task. Although many animals use simple tools, only human beings, whose use of stone tools dates ba ...

consisting of a ball or bulb (for example, of iron) which would be heated up attached to a long handle. Used to heat or melt solids and solidified liquids, it was formerly a fairly common tool. For example, loggerheads were used by shipbuilders to melt pitch. Although not its intended purpose, it was also used in American taverns in the 17th and 18th centuries in the making of the then popular mixed drink flip.

References

Tools Bartending equipment Heating {{tool-stub