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Friday, March 31, 2017

What's the conversion from avoirdupois to troy weight?

One of our patrons has a collection of silver, which, like all precious metals, is traditionally measured in troy weight. The standard weight used for almost everything else is called avoirdupois weight, from the Old French “avoir de peis,” which means “goods of weight,” and the two measurements are not equivalent. A troy ounce is a little larger than an avoirdupois ounce, but, because there are 16 ounces in an avoirdupois pound and only 12 in a troy pound, the troy pound is smaller.

In both units of measurement, the grain is the same: a little less than 65 milligrams (64.79891 to be exact). There are 437.5 grains in an avoirdupois ounce and 480 grains in a troy ounce. 1 troy ounce equals about 1.097 avoirdupois ounces (so, going the other way, 1 avoirdupois ounce equals about 0.911 troy ounces). 1 troy pound is about the same as 0.823 avoirdupois pounds. Reversed, that means that 1 avoirdupois pound equals 1.215 troy pounds.

Friday, March 24, 2017

What kind of ducks were on my pond?

“Can you tell me what kind of ducks were on my pond this morning? One was brown and the other one was darker but it had a big patch of white on its side. Both of them looked like they had white stripes on their beaks.”

We checked the Ohio Division of Wildlife’s waterbird identification guide and, while we weren’t able to precisely identify the ducks, we could narrow it down. Presumably, they were a male and female pair – the female is often drabber in color, so she was probably the brown duck.

They were not canvasbacks. While the female canvasback is brown and the male is black and rusty brown with a white body, they both have dark bills. The redhead is a possibility, but the colors don’t quite match up. Again, the female is brown and the male, like its name indicates, has a rusty red head and a black and grey body. Their bills are a lighter blue-grey, but they are black-tipped rather than white-striped. The lesser scaup also has a blue-grey black-tipped bill with a darker body and grey-white sides. The female is lighter in color but also has grey-white sides. Our patron’s birds could also be ring-necked ducks. Both the male and female ring-necked duck have white rings on their beaks. The female is brown with pale cheeks and the male is black with grey and white sides and a distinctive peaked head. All of these ducks are common across Ohio when they’re migrating.

If our patron happens to hear their ducks make sounds, they may be able to identify them that way. According to the Ohio Division of Wildlife, while the canvasback is usually quiet while it migrates, it can hoot and growl. The ring-necked duck also growls, hisses, and whistles. The redhead has a “low, nasal quack” and the male in spring makes “catlike” sounds. Finally, the scaup makes a sound that’s an onomatopoeia of its name.

EDIT: Sara from The Bridge, a Newton Falls newspaper, suggests that they may be mergansers, which are common across Ohio during their migration. 

Friday, March 3, 2017

Why is my ivy turning yellow?

This was actually a question from one of our librarians, who had received a potted ivy plant which she had been keeping by the library window. The plant was getting lots of sunlight, but the leaves were turning yellow. We checked The House Plant Encyclopedia by Ingrid Jantra and Ursula Krüger, What’s Wrong with My Houseplant? by David Deardorff and Kathryn Wadsworth, and Kristi Waterworth’s “Ivy Turning Yellow” article on to find out why.

According to Jantra and Krüger, ivy leaves may turn pale if they’re getting too much light, but, in general, yellow leaves are caused by too little light, a nutrient deficiency, or too much watering. Deardorff and Wadsworth agree. Evidently, it’s difficult to tell exactly what causes yellow leaves – they’re a symptom of some sort of problem, anything from fungus, insects, or a bacterial infection to the issues mentioned above. Waterworth adds that it may be something in the ivy’s environmental stressing it out. Dry air, high levels of salt in the soil (either from tap water or overfertilizing), or a draft can all make an ivy’s leaves go yellow.

Our librarian guessed that it may have been a draft, since her ivy sat in a cold window. She has since moved it and is waiting to see if its condition improves.