The Mid-Iron: One of Golf's Old Clubs
No, the mid-iron was a club used in the second half of the 1800s, the early parts of the 1900s. It is what we call today a vintage club or antique club, because it dropped out of the game when matched, numbered (1-iron, 2-iron, 3-iron, etc.) irons entered the game in the 1920s and 1930s.
The old mid-iron was a wooden-shafted, iron-headed golf club with a narrow blade and not much loft — but more loft than the driving irons in use at the time. In a golfer's bag, the mid-iron fell between the driving iron (or driving cleek) and the mid-mashie. As such, the mid-iron is often referred to as the equivalent of a 2-iron and, in fact, when numbered sets of irons came into the game the 2-iron was often referred to as "mid-iron," until the term began fading away.
Those old, named clubs, however, were used for a much larger range of shots than modern irons. The course conditions and quality of equipment in the early days of golf golf required much creativity and inventiveness in the use of every club.
For example, in Travers' Golf Book (affiliate link) by Jerry Travers, published in 1913, Travers, a U.S. Amateur and U.S. Open champ, wrote that "the mid-iron is the jack-of-all-trades of golf. One can drive, approach, putt and even get out of a reasonable amount of trouble with it."
But Travers also described the mid-iron this way:
"It is not the equal of the driver and brassie for distance, it is far inferior to the mashie for shots that require lofting, and as an ever-present help in trouble it by no means supplants the mashie niblick. Neverless ... the mid-iron is the 'handy club' of golf. Furthermore, although the iron clubs include the cleek, driving iron, mid-iron, jigger, mashie, mashie niblick and putter, the mid-iron alone has the distinction of being referred to as 'the iron'."In the Harry Vardon book The Gist of Golf (affiliate link), Vardon, just like Travers, calls the mid-iron his favorite club and says it is "without doubt, the handiest club in the golfer's kit."
"Just remember how often you find yourself between 120 to 170 yards from the hole," Vardon wrote, "which is roughly the mid-iron range. It happens repeatedly; at many holes after a good drive, and at many others after a foozle which left you farther from the green than you should be as a result of two shots. A lot of people take a mashie and, with a full swing, hit for all they are worth. If only they would repose their faith in the mid-iron and play a nice, easy, well-controlled shot with it, they would fare very much better."
It is a huge statement on the differences between golf in the late 1800s/early 1900s and today — conditions, equipment, distances, technique — that a narrow-bladed iron with the equivalent of 2-iron loft would have been considered a go-to utility club.