"Not snow, no, nor rain, nor heat, nor night keeps them from accomplishing their appointed courses with all speed."

That was easy enough for Herodotus to say back in 450 B.C. But he didn't have to sidestep Dobermans in Annandale or face up to a gentle (he's never bitten anyone before!) St. Bernard in Kansas City like the nation's letter carriers do, six days a week.

Dog-removes-the-seat-of-mailman's-trousers makes for a good cartoon. But it is a sick joke to the nation's postal workers who must regularly visit neighborhoods where unleashed pooches take a $7 million bite out of the taxpayers each year.

Hundreds of postal workers are injured annually -- some crippled for life -- as a result of dog bites. Last year the USPS spent $264,000 for 570,000 cans of dog repellent, which is designed to deter but not injure pooches who, contrary to popular opinion, do not love a man in uniform.

Now the USPS is testing a new weapon in its age-old war against dogs -- an umbrella. Specifically, a modified, short, pop-open umbrella that, backers say, repels even the fiercest canine when pointed in his (her) direction and popped promptly.

The snap-open umbrellas are being field-tested by postal workers in Sacramento, San Jose, Louisville, Salt Lake City, Seattle, and on Long Island. The British Postal Service is also studying the so-called dogbrellas.

If umbrellas become standard issue for letter carriers, the credit will go to Tom Meighan, a postal safety expert in Sacramento. He spent many years with the Air Force in the Orient where martial arts specialists abound. Meighan says the popping sound of the umbrella deters most dogs from attacking. He says the defensive device has been used many times on the street, with no bites reported.

The spray stuff the USPS now arms carriers with must hit the dog to be effective. It is supposed to be harmless, but can cause hard feelings from patrons who believe their dog wouldn't bite anyone.

The Postal Service can and does shut off delivery to homes --even entire neighborhoods -- where loose dogs are a problem. But that causes problems too. Hence the government has high hopes for the umbrella, which is cheaper than the financial loss caused by some dog attacks and also is handy when it rains.