Phillips Police Equipment Co., 931 H St. NW. Open Monday through Friday, 9:30 a.m. to 5 p.m., Saturday until 2 p.m. 783-1411.

The silver-lining school of philosophy could no doubt find handy

The silver-lining school of philosophy could no doubt find handy home uses for those big yellow boots the D.C. police lock onto illegally parked cars. They are, after all, a colorful addition to a block's street furniture, and can keep thieves from stealing your car. If you believe that, and want one of those boots for your very own, you can buy one at Phillips Police Equipment Company for $169.50 to $250. Or, if you prefer to act after the fact, you can buy fingerprint equipment. If you are the type who anticipates disasters, you can find fluorescent crayons for marking your valuables invisibly, or multi-stain theif-catching paste, or police-style key holders which attch to your belt and can't get lost unless you lose your belt. For meeting emergencies, they have a Sentry spray which is said to chase away animals and might be useful on hikes. Shrill alarms, which emit an irritating high-pitched sound, are said to chase away just about anybody. And boat horns chase boats or summon them, depending on your need at themoment. If you are anxious enough that you think you need a bullet-proof vest, however, you will h ave to shop elsewhere.