A window shelf that holds a collection of cobalt-blue bottles attracts attention, so many new collectors buy their bottles by color. Most early bottles were made of pale-blue or aqua glass. It was difficult to produce clear glass in the 18th and early 19th centuries.

Early bottles were blown, sometimes shaped by the maker or sometimes blown into an iron mold. A bottle had small imperfections caused by tiny pieces of sand or other ingredients. Dark colors were rare. By 1880, the quality of glass was improving.

Whittle marks and tiny bubbles were seen less often, and chemicals were added to make colored glass smooth. Amber, green, brown, light-blue and clear bottles were made to hold medicine, whiskey, soda, ink, mineral water and canned food. The most popular cobalt-blue color was made by adding cobalt oxide to the glass mixture.

The automatic bottling machine came into use in 1903, so cobalt-blue bottles seen most often today were machine-made. Many held medicine, like Bromo-Seltzer or Milk of Magnesia. These are very inexpensive. But old cobalt bottles made earlier can be worth hundreds of dollars.

Buying tips: Old bottles probably have pontil marks (a scar on the bottom), flaws and raised lettering identifying the contents or maker. Many new cobalt-blue figural bottles have been made. Bottles marked “Wheaton” on the bottom are new.


Q: We have a cast-iron wood-burning stove in our garage. The markings read, “Lakeside Foundry Co., Chicago, Ill., Bell-Wood, Windsor.” Can you tell us anything about it?

A: Lakeside Foundry Co. was in business from about 1902 until 1920, when the foundry was sold and the name became Lakeside Forge. Lakeside Foundry made stoves, bells, tableware and other items that were sold by Montgomery Ward. Windsor was one of the brands sold by Montgomery Ward.


Q: When I was 6 or 7 years old in the late 1930s, I played with a small tin toy boat that held a bit of water and below it was another compartment with a candle. When I lit the candle, it would heat the water and turn it into steam. The steam went through a small pipe to the water in the boat and propelled the boat forward. Can you give me more information about the toy?

A: Your toy boat has several different names. Most common is the name “pop-pop boat,” but it’s also called a “puf-puf boat.” It was patented by Frenchman Thomas Piot in 1891. Heat is created with either a candle or a small oil burner. The toys were popular playthings in the 1930s, ’40s and ’50s, but they lost favor when plastic toys took over the market. Collectors hunt for toys like yours, but they don’t pay more than $15 to $25 for a used boat. If yours were in its original and unopened package, it could sell for up to $50.