Volta, Daniel and Dancer established the principles of energy storage batteries between them. These were soon powering Americas’ telegraphy system. In fact in hindsight, they foreshadowed the metaverse of virtual communication. Callaud’s gravity cell followed in the 1860’s and took the baton a little further. It was not perfect, but it was progress.
Callaud’s Gravity Cell Takes Advantage of Specific Gravity Difference
Callaud – all history remembers of him is his name – used specific gravity differences between Daniel’s chemicals to his advantage. These were the dilute sulfuric acid and saturated copper sulfate in the two vessels. First, he did away with Daniel’s porous, un-glazed ceramic vessel.
Next, he placed a copper cathode at the bottom of a glass jar, and suspended a zinc anode just beneath the rim. Then finally he scattered copper sulfate crystals around the copper cathode, before filling the glass vessel with pure distilled water.
Zinc sulphate solution formed around the anode when Callaud drew stored energy from his gravity device. However, natural specific gravity differences kept this cloud away from the copper sulfate crystals at the bottom of the glass vessel.
Steve Teese observed in his treatise ‘History and Measurement of the Base and Derived Units’ how the cloud grew as the gravity cell discharged. The cell was fully depleted once the copper sulfate crystals were consumed. However, an operator could renew the contents.
But Unfortunately Callaud’s Ideas Were Not Really Practical
The design was the basis for its own undoing. Firstly, moving the cell disturbed the gravity separation. And secondly, it needed to be in continuous use or else the blue solution mixed with the other contents.
And so Callaud’s gravity cell faded from the pages of time, except for those containing energy storage history. Nobody knows anything more about Callaud, trust us we tried hard enough. But today we remembered his contribution in this post.
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