LMP: Licensed Under Marsh Patents

LMP toasters
A variety of toasters showing the LMP logo and 1906 patent date.
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LMP:
Licensed Under Marsh Patents

The "PAT. FEB. 6. '06" Notice on Early Toasters

Most toasters from around 1920, irrespective of the manufacturer, have a February 6, 1906 patent imprinted on them as well as a diamond logo with the initials "LMP". The patent date leads many people to believe they have found a toaster from 1906. In fact the date refers to Albert Marsh's patent of Nichrome while working at Hoskin's Manufacturing Co.

How did this come about?

Since Marsh invented and patented Nichrome wire, any manufacturer who wanted to use Nichrome had to pay a licensing fee. This is similar to today's computer makers who pay Microsoft to use its operating system. Manufacturers who didn't want to pay the licensing fee had the option of inventing their own heating wire (the modern computer analogy would be Apple developing its own operating system as well as making the hardware). Some companies did try to make their own toasting element, like this American Beauty Toaster with a solid panel element.

General Electric, with its third version of their Model D-12, tried to circumvent the Marsh patent by pretending the heating element used was something unique they developed called Calorite. GE was taken to court by the Hoskins Manufacturing Co. (holder of the Marsh patent) and stopped making products using the infringing alloy until the case was settled handsomely in Hoskin's favor.¹

To the left is a reprint from a 1918 Driver-Harris Company catalog. According to C. Fisher in Hazelcorn's Price Guide to Old Electric Toasters, "When G.E. lost the case brought against them by Hoskins, they paid beyond the judgement amount in order to acquire a part ownership of the patent. The very large sum involved enabled Hoskins to undertake major and highly successful expansion.

"Licenses making toasters, irons, bowl heaters and the like were required to label each item with the Feb. 6, 1906 date and LMP in a diamond (Licensed under Marsh Patents), althought the latter is sometimes missing. The patent expired in 1923, the alloy entered the public domain, and the notice disappeared from products.

"It must be assumed that any toaster carrying the LMP notice was made between 1915 (approx.) and 1923. (The notice would not be stopped on the day the patent expired, but only as soon as the maker had a chance to replace or alter the labelling."

So there you have it -- if you come across a toaster with the LMP diamond logo and/or the February 6, 1906 patent date, the date refers to the Nichrome patent and not the age of that particualr toaster.