….The Rebs. are still raiding around up in Maryland and Pa. Grant blew up a fortification in front of Petersburg last Saturday (a week) &, but for the bungling way it which it was done, the result might have been glorious. As it was, it was a failure. The engineer had a powder fuse which went out twice, and delayed the blowing up an and a half. Who would have supposed, in these days of galvanic batteries & copper wire, that anyone would have been so behind the age as to depend on a powder fuse put in a wooden box, when a sure thing could have been made of it at any instant with a galvanic battery & wire! I wish I had been down there to advise! But the thing is over – we were defeated, & all I hope is “better luck next time” – or, at least more science next time!….
Ever seen something practical, but it was just so mesmerizingly beautiful you couldn’t stop looking at it? You wanted to see it safe and protected forever as a piece of art…
That’s the way I feel about Fresnel Lenses. They were/are beautifully cut glass lenses used in lighthouses. Many are well over a hundred years old, and happily some of them have found safe homes in maritime or lighthouse museums.
Today, I’ll share briefly about how the lenses worked, a story about Fresnel lenses during the American Civil War, and a couple that I’ve seen in museums. Continue reading →
In 1802, an American sea captain published a book which changed the maritime world. More than just a sea captain, the author had taught himself math, sciences, and languages…and he wanted to make the world of sailing and voyaging safer for captains and crews.
The New American Practical Navigator became the guidebook for maritime voyagers in the 19th Century, and it’s still referenced today. Some might argue that this blog post is out of order since the book published prior to the War of 1812 and last week’s post talked about relations with Japan in the 1850’s. However, the far-reaching influence of Nathaniel Bowditch’s book makes it a relevant topic at just about any point in our study. So…without further ado, we’ll glance backward for a few moments to learn more about the author and then return to the mid-19th Century timeline marker to comment on the book’s effects. Continue reading →