448

Lot 448 - 1818 Capped Bust Half Dollar NGC MS64

Currency:USD Category:Coins & Paper Money Start Price:1,000.00 USD Estimated At:2,000.00 - 3,000.00 USD
Lot 448 - 1818 Capped Bust Half Dollar NGC MS64
1818 Capped Bust Half Dollar. The devices were struck with such force and energy by the dies that all design elements show boldly including the stars which, on bust halves, tend not to be well defined as a rule. The central hair is also crisp and bold. A lustrous, golden brown toned specimen of this early issue. The coinage of 1818 was struck on a hand-operated screw press; steam coinage did not begin at the Philadelphia mint until 1836.

Historical note: The inventors of this period sought to create a safer alternative to the steam engines of the time, whose boilers often exploded due to the high pressure of the steam and the weak materials. One such innovations was the Stirling engine, which could convert any temperature difference directly into movement.

The Stirling engine works by the repeated heating and cooling of a sealed amount of working gas, usually air or other gases such as hydrogen or helium.

Devices called air engines had been recorded as early as 1699 around the time when the laws of gasses were first set out. But it was Robert Stirling's innovative contribution of 1818 that he called the 'Economiser' now known as the regenerator which acted to retain heat in the hot portion of the engine as the air passes to the cold part and thus improve the efficiency.

During the nineteenth century the Stirling engine found applications anywhere a source of low to medium power was required , a role that would eventually be assumed by the electric motor at the century's end.
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