HAMPTON -- Digging for old bottles in dumps of by-gone days seems to be the "in" thing now-a-days. Everybody's doing it, or nearly everybody.

Ask any dyed-in-the-wool bottle digger why he does it and he can't say exactly, but the feeling must be similar to that experience in the gold rush days, or hunting for buried treasure. Or could it be like the mountain climber who climbs mountains because they are there, and present a challenge? The bottle digger knows there are bottles down there somewhere down in among old rusty tin cans and broken crockery. He feels the next scoop of the potato digger (the tool most of them use) might just turn up a find, an old and rare bitters bottle, for instance.

Numbered among the countless people across the nation who have taken up this fascinating hobby, are Glen Dalton and his wife Eileen of North Hampton. They've been digging for 3 years, they tell me, and have among their huge collection, some rare, beautiful and priceless specimens. The older it is the more beautiful, according to Glen's way of thinking, because he goes in a big way for anything from out of the past.

He has them all numbered and catalogued as to type, name and where found. His favorite, he says is a brown flask, with the words "Granite Glass Co." imprinted on one side, and on the other, "Stoddard, N.H.", and is known as a Stoddard bottle, a rare find, and coveted by many a digger. Other brown bottles of the same weight and texture COULD be a Stoddard, but the name on it makes it authentic.

"I pulled it out of a stonewall," he said, "and held my breath, hurriedly washing it in a nearby brook, and was thrilled to find it all in one piece." He has it displayed on the beam mantel of his fireplace, along with other favorites.

Colored ones are on sunny window sills, where the early morning sun casts a colorful spectrum on the kitchen floor. Others are set here and there through their new home, where they are placed to their best advantage.

The town of Stoddard has banned bottle digging now, since diggers came in by the score from all around, and were digging up everywhere, even on private property, without so much as a "by your leave." Since Stoddard once once a glass blowing factory, the chance of finding an original was too great a temptation to pass up.

Where is a likely location for a dump? Glen says somewhere in the vicinity of an old cellar hole. Another likely place would be back of a stonewall bordering a stream, where folks expected spring rains and swollen rivers to wash their dumps away. (Water pollution way back then?) Sometimes one can be found in a woods by a stonewall, and again in the cellar hole itself.

Asked how he happened to get started on such a hobby, he said he went out one day with a digger, and seeing a cellar hole, they stopped to investigate. The first thing they saw were two big snakes crawling out of a crevasse in the rocks. But then Glen spied a bottle and "I was a bottle digger from then on," he said. It turned out to be a Rush's Bitters, a rare find.

Bottle diggers examine their finds minutely, noticing every detail. Does it have an open pontil on the bottom? Does it have whiddle marks throughout? To the outsider these words might as well be Greek, but to the collector an open pottle is a little rough circular mark in the bottom which designates the spot where the glass blower finished blowing and cut off the glass. This is one proof that the bottle was made before 1900. After that, bottles were machine made as a rule, and are recognized as such by a seam up the side to the neck. Whiddle marks? Well, they're little diamond-shaped flecks throughout the glass. One often finds air bubbles, too, noticeable when the bottle is held up to the light.

Bitters bottles are the most sought after by the digger. On some, the word "Bitters" is plainly marked in the glass. Old Continental bitters, Glen says, were 80 to 90% alcohol, the remaining contents some herb or other. When a man felt "under the weather" a "swig" from his Bitters bottle made him feel better in jig time. Prohibition put an end to the manufacture of Bitters, as such, however.

"You can tell a lot about a family by their dumps," Glen says. A quantity of medicine bottles denotes a sick family. Gin and rum bottles in profusion means some member liked his liquor pretty well. One medicine bottle manufacturer, John Wyeth & Co. made one with a measuring cap top, and by turning the cap to a number on the bottle, after taking a dose, told you when to take the next one. These came in blue, similar to the milk of magnesia or alka-seltzer bottles of today.

Speaking of color, some collectors value most highly the bottles in striking colors, but Glen says if it's old he doesn't care if it's just plain colorless. Among his medicine bottles he has one found in a Bristol dump, a "gargling oil" bottle, it says on the side. Another named variety of bottles is the Rumford, an 8, sometimes 12-sided bottle, usually in green.

Among his collection of bottles, Glen has a group of ink bottles, in cobalt blue, aqua, green and amber, with the name "Carter" and date 1897 carved into them, which he numbers among his favorites.

One could say Glen knows his bottles, imbibing his knowledge from books he buys or takes from the library and from association with other collectors. Each bottle he shows you has a story connected with it, where he found it, when, and when and where it was made and for what purpose.

Occasionally I walk in my wood lot, bird watching, but now that I've talked with a bottle digger, and such an enthusiastic one, I may find myself looking for a possible dump location, instead.