Balls Out

Sunday, December 26th, 2010

When a steam engine runs hard, it runs balls out — literally:

Power is supplied to the governor from the engine’s output shaft by (in this instance) a belt or chain (not shown) connected to the lower belt wheel. The governor is connected to a throttle valve that regulates the flow of working fluid (steam) supplying the prime mover (prime mover not shown). As the speed of the prime mover increases, the central spindle of the governor rotates at a faster rate and the kinetic energy of the balls increases.

This allows the two masses on lever arms to move outwards and upwards against gravity. If the motion goes far enough, this motion causes the lever arms to pull down on a thrust bearing, which moves a beam linkage, which reduces the aperture of a throttle valve. The rate of working-fluid entering the cylinder is thus reduced and the speed of the prime mover is controlled, preventing over-speeding.

David Foster suggests that our society has been hit with a plague of sticky governors:

It strikes me that the role played by the legal profession and the financial industry is analogous to the role of an engine governor. Like the governor, law and finance are control systems; they are essential enablers and regulators of the activities of the rest of the economy. But also like the governor, the percentage of total system resources that they themselves consume should be reasonably small.

What would we think of a governor that scarfed up 30% of the horsepower of the engine that it was serving? Most likely, we would conclude that it was either poorly designed or inadequately maintained, or both.

There is no question that the legal and financial industries are both vital. Contracts must be drafted, disputes must be adjudicated, and capital must be allocated effectively. But the numbers of people in these industries, and the share of national income devoted to their compensation — along with related expenses such as buildings and computer systems — is perhaps excessive.


  1. Ross says:

    Add to “legal” and “finance” at least one more: “security apparatus”.

    Oh, heck, throw in “medical”, too.

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