In 1623 Wilhelm Schickhart built the first calculating machine, made of wood, and based on the idea of "Napier's Bones" (a multiplying device). It could add and subtract, and with help from an operator, multiply and divide.

• The "zero" was first used in India in 876 B.C.

• Female greenflies can bear live, fatherless, female offspring, each one containing all the genes of its mother. An embryo of a female greenfly can even have a smaller embryo inside its own womb, so that a greenfly female can give birth to a daughter and granddaughter simultaneously, both of them being equivalent to her own identical twins.

• The ball on top of a flagpole is called the "truck."

• Connecticut and Rhode Island never ratified the 18th Amendment banning alcohol.

• The term "dog days" has nothing to do with dogs. It dates back to Roman times, when it was believed that Sirius, the Dog Star, added its heat to that of the sun from July 3 to Aug. 11, creating exceptionally high temperatures. The Romans called the period "dies caniculares," or "days of the dog."

• Chocolate contains phenyl ethylamine (PEA), a natural substance reputed to stimulate the same reaction in the body as falling in love.

• The smallest known species of fish is Pandaka pygmea, found in certain creeks in the Philippines. It reaches an average length of 3/8 of an inch and a maximum length of 7/16 of an inch.

• In a Zurich, Switzerland, hotel, a sign in English reads: Because of the impropriety of entertaining guests of the opposite sex in the bedroom, it is suggested that the lobby be used for that purpose.

• In 1654 Ferdinand II, Grand Duke of Tuscany, devised the first sealed thermometer, the forerunner of the common mercury thermometer of today.

• The Minoans of ancient Crete, around 2000 B.C., had surprisingly advanced plumbing. Well-engineered drain systems, supply pipes and a flush toilet were found in the palace of Knossos when it was excavated in 1899.

• A species of sponge, the red sponge, can be pushed through a piece of fabric so that it is broken into thousands of tiny pieces. The animal does not die. Rather, all the pieces reassemble until the sponge is back to its original whole self and continues with its life.

• A fine-quality Persian rug, containing as many as 1 million knots in every 3 square feet, may last as long as 500 years before it wears out.

• A single lightning bolt may give off 3,750 million kilowatts of electrical energy. About 75 percent of this energy is dissipated as heat, raising the temperature of the surrounding air to around 27,000 degrees Fahrenheit and causing rapid air expansion which leads to sound waves of thunder that can be heard up to 18 miles away.

Wein is a Los Altos resident and published author.