Barometers

It stood out to me that Coppelius came to Nathanael as a barometer dealer in "The Sandman" since every scene with Coppelius throughout the story is so full of eye and seeing imagery, yet barometers were the least eye-centric of his wares, even though he is consistently referred to as a "barometer dealer" and only once an "optician". At first I was confused why an optician would be selling barometers, but apparently "by the latter part of the 17th century many...opticians began to become involved with detailed and magnificent ornate cabinetry and designs of...barometers", so it is not so strange that Coppelius was selling them as an optician. However, it is repeated so often in the story that is obviously carries significance. Apparently one of the most common models of barometers at the time of the publication of "The Sandman" was a storm glass, which was widely used to attempt to predict stormy weather. Therefore, it seems that this emphasis on Coppelius's profession of selling instruments that foreshadow inclement weather is used to parallel the turbulence brought about by Coppelius himself.