As we prepare for the next major solar eclipse in North America – mark your calendars for the 8th of April, 2024! – it’s fun to look back at Observatory records from previous eclipses. On May 10th, 1994, nearly 300 people congregated at the Observatory to take in the spectacle of a partial eclipse.
It’s worth noting that getting the full experience of totality requires a perfect combination of timing, location, and decent weather. Not simple.
This particular event was an annular eclipse, in which the moon’s apparent diameter was less than that of the sun, so that there was always a portion of the sun’s disc visible, creating an annulus (ring) when viewed along the path of greatest eclipse. Still amazing.
It’s not just telescopes at the Observatory. We also have a spyglass. What’s the difference?
There are a variety of potential optics for a telescope, using reflectors to reflect and focus light, using refractive lenses to bend and focus light, using mirrors to turn a beam around corners, using these in combination. Each has its pros and cons, and careful optical design and precise manufacturing work to gather lots of light, to provide good resolution and magnification, and to correct for optical aberrations.
And in doing all of that, the image reaching your eye or the camera sensor gets flipped upside down. Also in reverse, if you’ve got a mirror in your optical train. When looking at stars and deep sky objects, that’s not a big deal. “Up” is arbitrary in space. For terrestrial viewing, however, up matters. Seeing that incoming pirate ship upside down is disorienting. So a good spyglass keeps up as up.
1943!
It does so by using a Galilean refractor design, which has a concave lens in the optical assembly to avoid the upside-down flip. The resulting telescope is necessarily longer than a comparable refractor with convex lenses, and thus heavier. That weight tends to limit the possible objective aperture size, and the practical magnification limits are low. Still: very effective for spotting Edward Teach at a distance, or for identifying the four largest moons of Jupiter.
Binoculars, incidentally, manage to keep the world upright thanks to a set of prisms between the objective lenses and the eyepieces. Yet another handy trick in the optical design toolkit.
Not presented entirely without comment, as it’s hard to contain the urge toward snark. Yes, we know what this is and why it’s useful; yes, we know what they mean by “gender” and how F/F looks the same but changes things. Yes, yes.
At any rate: the cables which once needed this adapter are gone, as is the equipment it carried electronic messages to and from. Now we just have a block of metal and plastic and the opportunity to squint and say, “I’m not sure that’s how that’s supposed to work.”
In 1963, one could purchase a Standard Astro-Dome with a 17′ inside diameter for the low, low price of $14,667. It must have been a worthwhile investment, because we’re still using it 60+ years later with no plans to update or replace it anytime soon.
Among the stacks and stacks of old records and books at the Observatory, we have a substantial text discussing best practices for astrophotography from…
1895. Sweet.
You may read a scanned version online if so inclined. Fun to note that, broadly speaking, the difficulties remain. With every improvement in technology comes an increased ability to explore and a growing expectation of quality, so there’s always opportunity to do better. From page 2:
“In order to appreciate the accuracy with which the mechanical adjustments must be made, and the care with which they must be used, we should recollect that in a telescope of sixteen feet focal length, a second of arc is rather less than .001 of an inch, — a quantity quite invisible to the naked eye. We are required, therefore, to keep a mass of metal weighing several hundred pounds following the star with such accuracy, for perhaps an hour, that it shall not for any length of time shift to one side of the other from its true position by this amount.“
No one expects an antique box of chocolate bars – a Boston-based brand which went out of business in 1981 – to contain those candies anymore. We reuse boxes all the time, and the key factors are size and durability. D-cell battery boxes are in relatively high demand, for example; good size and sturdy. Chocolates boxes, it seems, were once just right for storing lots of glass plates. This was so long ago, though, that the original use has become somewhat obscure. (The glass plates. No one’s confused about the eventual fate of the chocolate bars.) Now the boxes are more intriguing than their contents.
Five cents seems reasonable.
Idle thoughts bubble:
What an interesting array of flavors! Belmont? Mallowfudge? Creole Nut? Presumably Caramallow is a caramel-marshmallow hybrid, whatever that meant in practice.
Why is it Coconut Cream, but all of the others are ordered as Cream Almond or Cream Walnut? (Cream Brazil Nut?)
“Pure = Wholesome” feels appropriately late-19th-century and kind of creepy.
“Rich In Food Value” feels appropriately early-20th-century and definitely creepy. Or possibly written by ChatGPT; still creepy.
For those nights at the Observatory when the temperature drops and it gets fiercely cold, we have a little extra insulation from the weather. You might not be able to do much with these on, but you can’t do much when your fingers cramp up, either.
Suitably sized for holding a coffee or hot chocolate while appreciating how a clear, dry night can really bring out the stars.
It’s not uncommon for any place to collect things and never quite discard them, and it only grows worse when there’s no single person in charge of them. On some old shelves at the Observatory, we have no shortage of 19th-century astronomical observations from all around the world. A few select favorites recently spotted: Havana, Cuba; Hyderabad, India; Tachkent (now Tashkent), Uzbekistan.
Oldest so far spotted: Washington Astronomical Observations, 1848.
Been around a while.
Part of the library collection since 1856. Wonder if the library knows? (We’ve put in a call to the proper folks, so no worries.)
We have a whole range of “old” telescopes at the Observatory which, depending on context, can mean state-of-the-art for the 1990s or the 1890s. This, most likely, is our oldest. It’s a lovely old brass refractor set on a fine wooden tripod, and with a properly-fitted eyepiece might work just fine. Not that we’re setting it outside anytime soon. It’s a showpiece!
How old is it? The acquisition date is currently unknown – probably recorded someplace in all of these stacks of papers – but certainly prior to 1886, because it wasn’t given to Bucknell University, but rather to the Lewisburg University, which is what this school was up until that point. That particular bit of information does confirm that it’s older than our big Clark refractor (1887) and our wee Ertel & Sohn transit telescope (1889).
Shiny!
“Presented *to the* LEWISBURG UNIVERSITY by Benj. Pike Jr. Optician 294 Broadway New York”
Second point of interest: Benjamin Pike, Jr. was located at 294 Broadway during 1843-44, as near we can tell. But the University at Lewisburg was founded in 1846. Benjamin Pike, Jr. lived from 1808 to 1864, giving us a reasonable last-possible year. So, um, wave your hands and call it circa [insert whatever]. It’s old, brass, and pretty cool.
It’s unclear who made the telescope, too. Pike (like his papa before him) was an optician by trade, and so would have known his way around lenses. None of the quickly-searchable web sources mentions telescopes, though, so maybe he just knew the right sort of gift for ol’ William Bucknell? It’s entirely possible another department on campus has a set of his award-winning surveyors’ tools. We’ve got theodolites in the closet – as one does – but none quite so vintage.
Disassembling some old wooden equatorial wedges – a means of adapting an altitude-azimuth telescope for sidereal tracking at a specific latitude – and look what’s scribbled on the inside!
“PAT MULLIN RULES <– HE ALSO DROOLS”
Two different sets of handwriting. Appears to be two different ballpoint pens. Not clear if Pat had any input on any of this, or even who Pat is.
It should be noted that one can both rule and drool. Perhaps there isn’t a great deal of overlap in that Venn diagram, but they aren’t mutually exclusive.
