HOUSTON -- What a difference just half a decade can make in the life of a city.

With the sort of bad timing that is the result of bad luck, the bad timing that any journalist can understand, Jan Morris, the travel writer, picked 1982 to celebrate Houston as ''the best hope the time can offer.''

She compared it to Queen Victoria's London, or New York or Chicago in their salad days. Houston was, she marveled, a city of centripetal forces, a city metastasizing, where the vocabulary ''is habitually in the future tense'' and the Sunday papers carried 40 pages of help-wanted ads. Few boomtowns ever boomed as Houston did between 1973 and 1982.

With the sort of bad timing that any politician can sympathize with, Kathryn Whitmire picked 1982 to become Houston's mayor. She came to power thinking that her task was to deal with the problems of pell-mell growth. She must be a glutton for punishment: she is starting her fourth two-year term. But she has the serenity of someone who can reasonably suppose that she has seen the worst.

Visitors to her office walk past a wall adorned with an admonition spelled out in large art deco lettering: ''Cities and Thrones Stand in Time's Eye.'' Houston does not need to be reminded of the impermanence of prosperity.

Houston became a focus of the national epidemic of schadenfreude (the emotion of the '80s: taking pleasure from the misfortunes of others) because of the fall of oil and natural-gas prices, first in 1982 and again in 1986. Houston had typified the Texas ''too much ain't enough'' spirit, but suddenly see-through skyscrapers -- new and empty -- became symbols of the city in which John Connally, Bunker Hunt and other high rollers were brought low.

In the 1970s, the state government ran surpluses of up to $3 billion a year. But every $1 drop in the price of a barrel of oil cost the state $100 million in revenues and cost the state economy $3 billion.

Texas had considered itself recession-proof, or at least the place where the recession came last and left first. Actually, the economy of the ''oil patch'' (Texas, Oklahoma, Louisiana) was in an inverse relation to the nation's economy. In the 1970s, when rocketing energy prices drove the nation into stagflation, Texas produced less and prospered. Oil production fell from 1.3 billion barrels in 1972 to 945.1 million barrels in 1981, but revenues rose from $4.5 billion to $31.7 billion. Natural-gas production fell from 8.7 trillion cubic feet to 7 trillion while revenues soared from $1.4 billion to $12.6 billion.

However, in 1982 Jan Morris had detected something evanescent about Houston. She recalled that the glory days of cities come and go. When Charles Dickens arrived by train in Chicago, the conductor boasted to him: ''You are entering the Boss City of the Universe.'' Morris said the future never lasts, that Houston's ascendancy would be as ephemeral as any other. She imagined Houston emptying itself ''in an exodus as terrific as its influx,'' Mexicans streaming back south toward the border, oilmen fleeing in their Gulfstream jets.

But great cities do not disperse, they diversify. Today Houston's largest employer is the Texas Medical Center. In this respect, Houston, the South's largest city, resembles some Rust Belt cities. The largest employer in Cleveland is a medical center. The largest in Pittsburgh is the University of Pittsburgh.

The oil patch did not use its wealth to prepare for a future insulated from the vicissitudes of oil prices. ''Oil,'' wrote The Economist of London, ''made the oil patch rich; it also made it feckless, lazy and conceited.'' The oil patch entered the 1970s relatively poor and far behind the rest of the nation in education and other indices of development.

Much of the money and many of the mores of the West come from extraction industries -- oil, gas mining. Such industries involve hard physical work and good luck, booms and busts. They are not industries that encourage attitudes conducive to husbanding resources and investing in the social and physical infrastructure needed for steady prosperity over the long haul. Extraction industries are bastions of rugged individualism. They do not encourage in the community a propensity for collective provision.

But now Houston is developing a saving diversity. One moral of its recent roller-coaster history is an old moral. It is that in the lives of cities, or nations, things rarely are as good or as bad as they seem. Another moral the nation should draw from this metropolis-as-microcosm is that the future has a way of arriving unannounced. Its arrival is jolting when people have not prepared for it. One way to prepare is by governing with a two-word truism in mind: Nothing lasts.