Simple Hygrometer
Curving backwards in low relative humidity.
This certificate is printed on paper stock that was then laminated on the upper surface with plastic laminate. A couple of years ago, I taped it to the bottom edge of a frame (containing another meaningless certificate). Sometimes it curls backwards, and sometimes it curls upward. I recently noticed that its curling direction indicates the ambient relative humidity (RH). As the RH rises, the rear paper layer tends to expand, while the plastic lamination cannot. This causes the certificate to curl upward (laminate on the interior of the curve). When the RH is quite low, the paper layer shrinks to a dimension that is less than that of the plastic laminate layer, so it curls backwards (laminate on the exterior of the curve). Although there is no quantitation indicated, its conformation clearly indicates the RH.
Why "Mason Shoes"? Back in 1966, I purchased my first pair of high-top (cap-toe) dress shoes. (They were not at all the current fashion. My peers considered them "grandpa shoes".) For the next ~30 years, the only shoes I wore on a daily basis were similar, high-top dress shoes—sometimes black; sometimes brown; preferably made of supple, kangaroo leather. As they became more difficult to find at a reasonable price, I finally, in 1998, resorted to mail-ordering a pair from Mason Shoe Company. The company finally went belly-up 5 years later—at the age of 99.
Mason Shoe was founded in 1903. It is Mason Shoe that accounted for the door-to-door shoe salesmen that spread out across the country during the Great Depression. [I actually invited into my house a door-to-door Fuller Brush salesman—box-like suitcase in hand—in Berkeley, CA, back in 1977. I purchased 3 brushes, just for the memory.] Well, when I ordered my final pair of high-top dress shoes from Mason Shoe, in 1998, they included this laminated "Authorization" in the box. I found it amusing enough to keep the certificate for the past quarter century.
So in a gesture to recycling, I now have a hygrometer on my living room wall.
Bob
Curving backwards in low relative humidity.
This certificate is printed on paper stock that was then laminated on the upper surface with plastic laminate. A couple of years ago, I taped it to the bottom edge of a frame (containing another meaningless certificate). Sometimes it curls backwards, and sometimes it curls upward. I recently noticed that its curling direction indicates the ambient relative humidity (RH). As the RH rises, the rear paper layer tends to expand, while the plastic lamination cannot. This causes the certificate to curl upward (laminate on the interior of the curve). When the RH is quite low, the paper layer shrinks to a dimension that is less than that of the plastic laminate layer, so it curls backwards (laminate on the exterior of the curve). Although there is no quantitation indicated, its conformation clearly indicates the RH.
Why "Mason Shoes"? Back in 1966, I purchased my first pair of high-top (cap-toe) dress shoes. (They were not at all the current fashion. My peers considered them "grandpa shoes".) For the next ~30 years, the only shoes I wore on a daily basis were similar, high-top dress shoes—sometimes black; sometimes brown; preferably made of supple, kangaroo leather. As they became more difficult to find at a reasonable price, I finally, in 1998, resorted to mail-ordering a pair from Mason Shoe Company. The company finally went belly-up 5 years later—at the age of 99.
Mason Shoe was founded in 1903. It is Mason Shoe that accounted for the door-to-door shoe salesmen that spread out across the country during the Great Depression. [I actually invited into my house a door-to-door Fuller Brush salesman—box-like suitcase in hand—in Berkeley, CA, back in 1977. I purchased 3 brushes, just for the memory.] Well, when I ordered my final pair of high-top dress shoes from Mason Shoe, in 1998, they included this laminated "Authorization" in the box. I found it amusing enough to keep the certificate for the past quarter century.
So in a gesture to recycling, I now have a hygrometer on my living room wall.
Bob
