The Eclipse Of 1780

Soon after its foundation in the seventeenth century, Harvard University instigated the study of physics. In 1726 a benefaction from

FIGURE 8-1. This drawing of Christopher Columbus using the lunar eclipse of February 29, 1504, which appeared in Washington Irving's Life and Voyages of Christopher Columbus in 1892, gives a rather different impression to that shown in Figure 3-5, which is from a few decades earlier. This depiction shows Columbus in a more benevolent light, garbed in fine clothes and with the Jamaicans at his feet, whereas the other picture has him armed with a sword and closely accompanied by armed guards.

FIGURE 8-1. This drawing of Christopher Columbus using the lunar eclipse of February 29, 1504, which appeared in Washington Irving's Life and Voyages of Christopher Columbus in 1892, gives a rather different impression to that shown in Figure 3-5, which is from a few decades earlier. This depiction shows Columbus in a more benevolent light, garbed in fine clothes and with the Jamaicans at his feet, whereas the other picture has him armed with a sword and closely accompanied by armed guards.

an Englishman, Thomas Hollis, led to the endowment of a professorial chair of "Mathematicks and Experimental Philosophy." It continues to this day.

The second occupant of that chair was John Winthrop, who was appointed in 1738 at the age of 24 and held the position until his death at 65.Winthrop is often regarded as the first true "American astronomer," and he made observations of many celestial phenomena. In particular he was involved with timing the transits of Venus, a subject we discuss in Chapter 13. It seems though that

Winthrop's attainments in physics were not so wonderful, and it is not clear from the notes he left that he even understood Newton's laws of motion, one of the most rudimentary facets of the science. Winthrop's demise led to the appointment of Samuel Williams, just in time to start planning for the solar eclipse anticipated for October 27, 1780. The track of totality was expected to pass over much of Maine and parts of maritime Canada.

There was an obvious problem. This was the time of the Revolutionary War, and the track lay within enemy (i.e., British) territory. Undeterred, Williams made his calculations, studied his maps, and chose the western part of Penobscot Bay in Maine as a suitable observation point. This choice was based largely on the need to bring in a large sailing ship carrying the heavy equipment required for the eclipse observations: the telescopes, clocks, and so on. This decided, Williams prevailed upon John Hancock, the first signatory to the Declaration of Independence and in 1780 the Speaker of the Continental Congress, to write to the commander of the British forces. "Though we are political enemies, yet with regard to Science it is presumable we shall not dissent from the practice of all civilized people in promoting it," wrote Hancock. After such sweet-talking, safe passage was granted to the party.

On October 9 a group of four faculty members and six students set off up the coast in a boat supplied by the Commonwealth of Massachusetts. On arrival in Penobscot Bay they set up their equipment, calibrated their clocks with other astronomical observations, and confidently awaited the eclipse. This duly arrived, starting in the middle of the morning and reaching a peak shortly before noon. There was just one problem: They did not witness totality. The visible fraction of the solar disk shrank to a sliver, but it did not disappear. Williams's calculation of the eclipse track was wrong. It turned out that they should have been positioned at least 30 miles further north.

The embarrassment over the failure of this official expedition was made even more acute by the fact that on the British side Dr. John Clarke, a Harvard graduate, had successfully witnessed the eclipse from Prince Edward Island. Accompanied by Thomas Wright, the local surveyor general, Clarke used a small telescope to make observations, and then sent the results to the American Academy of Arts and Sciences.

What went wrong with the expedition led by Williams has long been a mystery. In an attempt to throw light on the matter, on the bicentenary of the eclipse in 1980, a new expedition of Harvard staff and students returned to Penobscot Bay, taking with them maps and instruments identical to those used by Williams and his group. All worked precisely as they should, although there have been questions raised as to whether the times of the eclipse contacts reported by Williams, and the extent of the arc of the Sun seen as remaining uncovered, were consistent with the stipulated observatory site.

Explanations for the blunder fall into three categories. The first is that Williams simply made a numerical error in his sums. The second is that the map used was inaccurate, showing the wrong latitude for the bay. The third category is connected with errors in the astronomical tables from Europe used by Williams. Although there seems to be inadequate documentary material left in order to know whose fault this farce was, it has been usual to lay the blame at the door of Samuel Williams. Both during this first American eclipse expedition, and in later life, he did a number of things that might be regarded as imprudent. But there is not the evidence necessary to be sure of his guilt here.

There is someone else who was greatly unhappy at turns of events on October 27, 1780, in this case for an entirely different reason than the failed eclipse expedition. This story involves another of the signers of the Declaration of Independence, Francis Hopkinson. Despite a widespread belief that Betsy Ross designed the Stars and Stripes, in fact it was Hopkinson who was responsible some years earlier. He invented not only the basic design for the flag of the United States, but also various other insignia and seals. With some justification he felt it was his due that this should be recognized and some nominal amount paid to him. On the same date as the eclipse the Treasury Board presented its report to Congress and recommended that because Hopkinson was already in the government's employ he should receive no further payment. In consequence he resigned in disgust. After all, he had only asked for a "quarter cask of the public wine" as a token of gratitude.

Telescopes Mastery

Telescopes Mastery

Through this ebook, you are going to learn what you will need to know all about the telescopes that can provide a fun and rewarding hobby for you and your family!

Get My Free Ebook


Post a comment