A Giant Thermometer?

 

The Victoria Bridge consists of 12 double iron tubes and one centre tube; about 2 inches of space between each section is left for expansion and contraction, the tube being placed on rollers, for it must be observed that the great bridge never rests—it is constantly on the move. When the temperature sinks to 20 below zero, 24-30 inches of this massive structure actually disappear from view, to be restored again in full when the summer sun sends up the thermometer to 90 in the shade. The late Mr. T. D. King, of Montreal, one of the early officers of the G.T.R., a lover of art and science, took advantage of this contraction and expansion in the tubes, and made the big bridge register its own movements. He erected a framework with a scale of degrees upon it, which rested on the stonework of the first pier of the Bridge, alongside a section of the iron tubes. Mr. King was wont to tell his friends that the Victoria Bridge showed so many degrees above or below zero, as the case might be.

Source: M. Pennington, Railways and Other Ways, (Toronto: Williamson & Co., 1896) p. 99.

 

Did you know that a Thermometer is an instrument for measuring temperature using a substance whose expansion and contraction under different degrees of heat and cold is capable of accurate measurement?

Did you know that bridges are made of substances whose expansion and contraction can be measured accurately?

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