norman-lockyer

How Norman Lockyer Discovered Helium, Chromosphere And Nature Magazine

How did Norman Lockyer go from being a poor civil servant with no scientific background, to a famous astronomer who co-discovered and named the Chromosphere of the sun, determine that lines in the chromosphere were from a new element, named that new element Helium (after the Greek God of the sun Helios), and create and run one of the most influential science magazines of all time: Nature?



Table Of Contents

How A Civil Servant Became an Important Astronomer

How Spectroscopy Changed Astronomy

Lockyer and Sunspots

How Lockyer discovered the Chromosphere

Why Lockyer and Janssen are Co-awarded the Discovery

How Helium was Discovered by Lockyer

The Start of Nature Magazine

The Search for Helium on Earth

References

Video Script Download


How A Civil Servant Became an Important Astronomer

Norman Lockyer Portrait
Norman Lockyer Portrait

I want to begin in around 1861 when Norman Lockyer was a bored 25-year-old 2nd class clerk and linguist for the War Office in Wimbledon, England.

At the time, Lockyer used to regularly commute to London and he became friendly with a fellow commuter who had a 3 ¼ inch telescope that was gathering dust.

Lockyer’s friend loaned the instrument to him and he was instantly hooked. 

Soon, the young man bought his own cheap telescope and started making observations and although his reflections were enough to get him admitted to the Royal Astronomical Society in 1862, it sure didn’t pay the bills. 

Then, two things happened that changed his life. 

First, he met a telescope manufacturer named Thomas Cooke who was so impressed with Lockyer that he promised him a 6 ¼ inch lens if Lockyer could build his own tube to hold it, which Lockyer did with paper maché and scrap metal (a slightly improved version of this telescope which he made in 1871 is still in use today)! 

The second thing that happened was that in that same year of 1862, his neighbor asked him to be the science editor for a new journal named The Reader to discuss science, religion and art. (He was hired because he was smart, hard-working, had lots of friends and as one of the owners wrote, “he will do the work too gladly at a lower figure than any other competent man”). 

This caused Lockyer to contact every prominent scientist in England to try to get more articles for his paper (including Charles Darwin and his influential friends). 

Lockyer’s wife, Winifred, also got into the writing business when she helped her husband translate a French book of astronomy called “The Heavens” which her husband edited in 1867.  Winifred Lockyer was so proficient at translations, and Lockyer was so busy, that she started to do all the translations and was finally credited for her work.

Soon, she was, according to Lockyer’s biographer, “so successful that she was immediately accepted in the publishing word as a leading translator of French scientific texts”, and Winifred’s translations and Norman’s writing kept them in the black, but barely.  

How Spectroscopy Changed Astronomy

Sir Joseph Lockyer (b. May 17, 1836, Rugby, Warwickshire, Eng.--d. Aug. 16, 1920, Salcombe Regis, Devon), British astronomer who in 1868 discovered in the Sun's atmosphere a previously unknown element that he named helium.
Sir Joseph Lockyer (b. May 17, 1836, Rugby, Warwickshire, Eng.–d. Aug. 16, 1920, Salcombe Regis, Devon), British astronomer who in 1868 discovered in the Sun’s atmosphere a previously unknown element that he named helium.

Meanwhile, in the mid 1860s, Lockyer and his wife learned about the brand-new method of astronomy called spectroscopy, or using a prism to look at the colors of light produced by burning materials to determine the nature of stars and the sun. 

See, in 1859, a German scientist named Robert Bunsen used his new burner to determine that burning solids and liquids basically make a continuous rainbow but burning gasses make distinct bands of light, an “optical fingerprint” that was different for every element they could find. 

Bunsen also found that sodium gas would produce distinctive double bright yellow lines and, as it only produced those two colors in the visible spectrum, these bands were particularly bright. 

In fact, it was so sensitive that they could see sodium when as little as 1/20,000,000th of it was suspended in smoke!  Then, Bunsen’s best friend, Gustav Kirchhoff, had the random idea of burning sodium in front of lamp light. 

As his lamp produced, basically, a continuous spectrum and the sodium gas produced two bright yellow bands, he assumed that this combination would produce a rainbow with extra bright bands superimposed on it. 

Instead, he was shocked to look in the yellow spectrum and find two dark black bands, “exactly at the spots where the bright lines were supposed to show.” Kirchhoff realized that he had the clue to solve a 45-year-old mystery of sunlight called “Fraunhofer lines”. 

Back in 1814, Joseph Fraunhofer found that when you look really closely at sunlight through a prism you see a rainbow with dark shadows in it with two dark lines in the yellow at the exact same spot as the bright yellow from burning sodium, labeled the D lines as they are the fourth dark line in sunlight.  

Therefore, in 1859, Kirchhoff immediately recognized that the center of the sun must be making a continuous spectrum like his lamp and the gases in the sun’s atmosphere were absorbing the particular frequencies depending on its element. 

All you needed to do was find the bright lines that elements make on Earth, find the corresponding dark lines in the sunlight, and presto-chango, you know what is in the atmosphere of the sun. 

This was the first method to know what stars are made of, and it is still a staple of Astronomy to this day. Bunsen and Kirchhoff found not only sodium but also hydrogen, iron, and even gold lines in the sun but no helium, as no one knew about helium… yet.  

Lockyer and Sunspots

Back to Lockyer, through his publishing work, Lockyer became very close friends with a Scottish astronomer named Balfour Stewart who was in a vigorous debate with other scientists about the nature of sunspots. 

Some scientists thought that the interior of the sun was cooler than the exterior and sun spots were windows to the cooler interior whereas Stewart (and others) thought they were from areas of thicker (and cooler) atmosphere which absorbed more sunlight. 

In March of 1866, Lockyer decided to try to experimentally determine the truth by studying sunspots with spectroscopy.  He knew that a sunspot, like any dark shadow is not actually an area of no light, merely an area of less light than the area around it (although the brightness of the rest of the sun makes them appear black). 

Therefore, Lockyer used a telescope to focus the light from the sun on a screen and placed a slit on the light from the sunspot and then used a prism to determine the spectrum of light from that spot. 

He then found that the absorption-bands from the atmosphere were “visible in the spectrum of the spot; they, moreover, appeared thicker where they crossed the spot-spectrum.” In other words, the sunlight from the sunspot had more absorption than the rest of the sunlight and in this way Lockyer validated that Stewart’s theory with spectroscopy.

How Chromosphere was Discovered by Lockyer

Just before the success with the sunspot, Lockyer and Stewart had a discussion about the “strange red flames” seen around the sun in a total eclipse and came to the conclusion that it must be “masses of glowing gas” in the corona. 

Lockyer wondered if he could use spectroscopy to solve the mystery and some of his last words in his paper on sunspots were, “may not the spectroscope afford us evidence of the existence of the red flames which total Eclipses have revealed to us in the Sun’s atmosphere?”.

It was logical that these flames were always there but blotted out by the bright light from the center of the sun, but Lockyer hoped that a spectroscope focused on the edges would work. 

However, Lockyer, “diligently swept round the solar disk [with a spectroscope] in search of evidence of the red flames, but without result,” a failure he attributed to the, “excessive brilliancy” of the sun.  Undeterred, he realized that he needed a way to weaken the continuous spectrum from the sun without dimming the light from the “red flames”. 

Now the light from the center of the sun temporarily during a solar eclipse and a total eclipse was predicted in August of 1868.  However, Lockyer did not have the patience to wait for over two years nor did he have the funds to travel to India where the eclipse was visible.  Instead, Lockyer came up with a clever idea on how to remove the continuous spectrum from the sun without an eclipse. 

He knew that a prism spread out the light from the sun and wondered about using more than one prism.  With more prisms, the continuous spectrum would dispersed more, and therefore become weaker, however, the light from the atmosphere was at specific frequencies and would not be dispersed or spread out by the prisms no matter how many you use. 

Therefore, if you use a lot of prisms in a row you can dim the continuous light from the sun without dimming the distinctive light bands from the glowing gas in the atmosphere.  

Lockyer attempted to blot out the sun with multiple prisms in 1866, but his equipment wasn’t good enough and so he applied for and won a government grant in early 1867 to get better equipment. 

Lockyer immediately turned to his friend Thomas Cooke who had given him a lens for his paper maché telescope in 1862, but unfortunately, Cooke’s health was failing and by the end of 1867, Cooke had to give up on the project and Lockyer had to turn to another telescope designer. 

This was why Lockyer only received his special spectroscope with seven prisms in a circle on October 16th of 1868.  Four days later, on October 20th, Lockyer, used his system with and, as he described it a few weeks later, “I saw a bright line flash into the field [and] my eye was so fatigued at the time that I at first doubted its evidence, although, unconsciously, I exclaimed ‘At last’! The line, however, remained – an exquisitely colored line absolutely coincident with the line C of the solar spectrum… I quitted the observatory to fetch my wife to endorse my observation.” 

That day he also found two more bright lines: one “nearly coincident with F” and one “near D”, where the one near D was off of the regular D lines. 

Lockyer published his findings as a quick note the very next day to the Royal Society of London.  Lockyer had proved that the flames around the sun were, just as Lockyer and Stewart predicted, a glowing gas! 

Belfour Stewart immediately sent a letter to a friend in France with the title “Lockyer is triumphant, he found red flames with a new spectroscope.”  

Why Lockyer and Janssen are Co-awarded the Discovery

This letter (and a second, longer letter written two days later) were read to the French academy of sciences five days after the first letter, on October 26, 1868,.  However, because of the delay in equipment, Lockyer’s experiment was conducted two months *after* the total eclipse in India.

One of the many European scientists who could get the funds to go see the eclipse was a 44-year-old French astronomer named Jules Janssen. 

Now Janssen, like Lockyer, was interested in spectroscopy and used it on the sun, whereupon he immediately sent a telegram to a friend declaring: “Eclipse observed, protuberances, spectrum very remarkable and unexpected, protuberances [are of] gaseous nature.” (p.494

Not only that but after realizing that the red flames around an eclipse were emitting bright bands of light, where most of the lines corresponded to the gas hydrogen or, as he put it, the red “flame”, “formed by an immense incandescent gas column, mainly composed of hydrogen gas,” Janssen then came to the same conclusion as Lockyer had done 2 years earlier.  Namely, Janssen decided that since the “red flames” produced distinct bars of light he could study them at any time, “without the need to use the interposition of an opaque body in front of the sun’s disk.”

Janssen was a far more experienced astronomer and actually concocted a special multi-prism spectroscope on the spot, and successfully used it the very next day, nearly two months before Lockyer’s experiment!  However, as Janssen didn’t know about Lockyer, he was in no rush to publish and, after sending a note to a friend a few weeks later, went on a scientific trip to the Himalayas.  

That was why, on the same day that Stewart’s letter about Lockyer’s success was read to the Paris Academy, Janssen’s friend was inspired to stand up and read Janssen’s letter as well. 

They were even printed in sequence in the Paris Academy of Sciences!   Despite the lack of detail from both men, the scientists at the Paris Academy were thrilled and amazed with the discovery that the sun had more complexity than expected and how they had used prisms to prove that at least part of the sun was made of gas.

An astronomer named Herve Faye was motivated to clarify the “singular coincidence of the discoveries which have just been presented at the academy.” Faye then described how it was clear that Lockyer had come up with the idea first, at the end of his paper about the sunspots in 1866, but Janssen discovered it first, but had just not had time to publish it yet.

Faye added that you could split the honor in two: Lockyer being the first with the idea and Janssen being the first to succeed, but Faye countered, “isn’t it better to attribute the whole honor to both of these two men of science who have separately, from thousands of miles apart, the joy of discovering [the nature of the sun using] the most astonishing way forward that the genius of the observation ever designed?”     

From that point on, scientists in France attributed everything to both men, which was quite advantageous to Lockyer, as Janssen was already famous and accomplished and Lockyer was far less known, especially in France. 

Janssen took the news very well and wrote a friend that if he had known about Lockyer’s project, “I would have immediately communicated by the telegraph the results I was obtaining in India.

I do not regret that Mr. Norman Lockyer has managed to confirm his ideas separately. I think he deserves it.”  The friend then published his letter, and Lockyer and Janssen began communicating and formed a quick and lifelong friendship. 

In fact, Lockyer dedicated his 1874 book on Solar Physics to Balfour Stewart and Jules Janssen: writing “Encouraged by one friend [Stewart] I undertook the work which has brought me the other [Janssen].”  

How Lockyer Discovered Helium

Meanwhile, Lockyer spent every clear day he could studying the lines with his new spectroscope. 

He found that these lines entirely enveloped the sun, but sometimes they were thicker where the gas flamed out in those red protrusions. 

As it was all around the sun, but was different from the rest of the sun, Lockyer decided it was a part of the sun’s composition and, therefore needed a new name. 

In November, 1868, mere weeks after his first observation, he suggested the name chromosphere – which literally means colorful sphere – and the name is still used to this day. 

Lockyer also found 4 clear lines in the chromosphere, at C, near D, at F, and at h. However, when he looked closer to the sun’s surface, he found more lines, including the twin lines at D that correspond to Sodium. 

This made sense to him, and validated that the chromosphere was composed of many elements but most of them are too heavy to be too far from the sun, or as he put it, “the reason that these do not reach up so far from the body of the sun is that their vapors are very much heavier than the gas hydrogen, which is the lightest terrestrial substance known.”  Still, Lockyer had a puzzling result. 

The 3 of the 4 bright lines he found far from the sun corresponded exactly with hydrogen, which was logical.  But one line, the one near the double D of sodium, did not. 

What was that mysterious line?  At first, Lockyer thought as the errant D line was found far from the surface of the sun, it must be from hydrogen, maybe at high pressure or temperature or something. 

For example, on July 8, 1869 Lockyer said that his bright line near D which he observed on October 20, 1868 was a Hydrogen line to which the editor George Gabriel Stokes added a footnote that just said Hydrogen – question mark .  

Lockyer was not a Chemist so he turned to a friend named Edward Frankland and they did everything they could to recreate this new D line with pressured hydrogen. 

But by April, 1870, he and Frankland decided that the new line could not be created with hydrogen and must be a new substance not found on Earth and only in the stars! 

A few years later, Lockyer noted that, “A line in the yellow of the spectrum will also be noticed.  This is one which has caused a great deal of discussion, for it is not coincident with any known terrestrial [terrestrial means Earth bound] substance known.”  

The Start of Nature Magazine

A facsimile of the first edition of Nature, 4 November 1869.
A facsimile of the first edition of Nature, 4 November 1869.

Meanwhile, two years earlier, in 1868, while studying the chromosphere Lockyer had also published a schoolbook on astronomy that was very popular and in 1869, convinced his publisher to let him start a science magazine called “Nature”. 

With his famous friends, this magazine turned into a grand success. Lockyer was the editor and owner of ‘Nature’ for the next 50 years until his death in 1920 and it is still going strong. 

According to Wikipedia, Nature is, “one of the world’s most-read and most prestigious academic journals”!   Anyway, in 1871, Nature published the inaugural address of William Thomson AKA Lord Kelvin for the “British Association”, which as far as I can tell is the first mention of the name helium. 

In this address Thomson told how the eclipse of 1868 proved that a “sensible part of the light” of the sun is from “glowing hydrogen and ‘helium’” where the word helium was in quotes with a footnote that: “Frankland and Lockyer find the yellow prominences to give a very decided bright line not far from D, but hitherto not identified with any terrestrial flame.

It seems to indicate a new substance, which they propose to call Helium” (the Helium was supposedly after the Greek god of the sun Helios).  

For many years, scientists assumed that Helium was only in the stars, however, in 1881, an Italian scientist named Luigi Palmieri found helium on Earth when studying material found during a recent explosion of Mount Vesuvius. 

Despite the fact that he was quite clear that he found helium writing, “Having analyzed this sublimated substance with a spectroscope, I recognized … a very distinct linear line which corresponds exactly to D3, which is that of helium,” his discovery was completely ignored by scientists in England, France and Germany and was only mentioned by many people in retrospect.  

For Lockyer, it was only in March of 1895, 26 years after Lockyer and Stewart named helium after a gas hidden in the sun, that a Scottish Chemist named William Ramsey discovered helium on Earth while trying to create argon gas. 

Ramsey immediately gave a vial of the new substance to Lockyer to examine as a sign of respect although Ramsey was the far superior Chemist and had already determined that this was helium with accuracy. 

Six months later, some Swedish Chemists managed to make enough Helium by a different method than Ramsey and they determined its atomic weight and proved that yes, Helium, is very, very light, second only to hydrogen. 

And that is how Lockyer went from being a patent clerk to a famous scientist and how he discovered and named the Chromosphere, helium and the magazine Nature.  


References / Citations:

1 According to the article on “Normal Lockyer Observatory” found in Bradt, H and Booth, J East
Devon and the Jurassic Coast (2016) p. 158
2 Baldwin, M Making ‘Nature’: The History of a Scientific Journal (2015) p. 25
3 According to the article on “Normal Lockyer Observatory” found in Bradt, H and Booth, J East
Devon and the Jurassic Coast (2016) p. 158
4 Thomas Hughes to Huxley (November, 1862) found in Meadows, A Science and Controversy, a
Biography of Sir Norman Lockyer (2016) p. 5
5 Meadows, A Science and Controversy, a Biography of Sir Norman Lockyer (2016) p. xxx
6 Bunsen, R and Kirchhoff, “Chemical Analysis by Spectral Observations“ The Laws of Radiation
and Absorption p. 108
7 Helmholtz, R “Gustav Robert Kirchhoff” The Open Court Vol. 2 (1889) p. 785
8 Lockyer, J “Spectroscopic Observations of the Sun” Proceedings of the Royal Society of London
Vol. 15 (Jan 1, 1867) p. 257
9 Lockyer wrote that he talked to “my friend Dr. Balfour Stewart” about eclipses in Lockyer, J
Contributions to Solar Physics (1874) p. 211
10 Lockyer, J “Spectroscopic Observations of the Sun” Proceedings of the Royal Society of London
Vol. 15 (Jan 1, 1867) p. 257
11 Lockyer, J “Spectroscopic Observations of the Sun – No. II” (November 19, 1868) Proceedings
of the Royal Society of London Vol. 159, p. 425
12 According to Lockyer, J “Spectroscopic Observations of the Sun – No. II” (November 19, 1868)
Proceedings of the Royal Society of London Vol. 159, p. 425
13 Lockyer, J “Spectroscopic Observations of the Sun – No. II” (November 19, 1868) Proceedings
of the Royal Society of London Vol. 159, p. 426
14 Lockyer, J “Notice of an Observation of the Spectrum of a Solar Prominence” Proceedings of
the Royal Society of London Vol. 17, p. 92-3
15 Belfour Stewart to Warren De la Rue (October 21, 1868) Compte Rendu de L’acaemie des
Sciences (July – Dec, 1868) p. 836
16 The date is on page 813!
17 Janssen “Indication de quelques-uns des resultants obtenus a Concanada, pendant l’eclipse…”
(Oct 26, 1868) Compte Rendu de L’acaemie des Sciences (July – Dec, 1868) p. 838
18 Janssen “Indication de quelques-uns des resultants obtenus a Concanada, pendant l’eclipse…”
(Oct 26, 1868) Compte Rendu de L’acaemie des Sciences (July – Dec, 1868) p. 838
19 “M. Faye demande ensuite la parole et s’exprime comme il suit” (Oct 26, 1868) Compte Rendu
de L’acaemie des Sciences (July – Dec, 1868) p. 840
20 “Vous connaissez maintenant la méthode que j’ai proposé pour l’étude des protubérances, et
dont Mr. Norman Lockyer avait eu l’idée, m’écrit-on, depuis deux années. J’ignorais cela, et
c’est une circonstance qui a été favorable à Mr. Lockyer; car si j’avais su qu’on travaillait sur ce
sujet, naturellement j’aurais, en citant l’idée émise, fait connaître immédiatement par le
télégraphe les résultats que j’obtenais dans l’Inde. Mais je ne regrette pas que Mr. Lockyer soitparvenu séparément à la confirmation de ses idées.” Janssen, M. “On the Solar Protuberances”
(Feb 2, 1869) Proc. Royal Society London Vol. 17 p. 276-7
21 Lockyer, J Contributions to Solar Physics (1874) dedication
22 Lockyer, J “Spectroscopic Observation of the Sun, No. II” (Nov 26, 1868) Proc. R. Soc. Lond.
Vol. 17 p. 132
23 Lockyer, J The Spectroscope (1873) p. 78
24 Lockyer, N “Spectroscope Observations of the Sun – No. V” Proc Royal Society of London Vol
18 p. 74
25 Lockyer, J “Spectroscopic Observations of the Sun – No. VI” (April 27, 1870) Proc Royal Society
of London Vol. 18 355
26 Lockyer, J The Spectroscope (1873) p. 78
27 “Inaugural Address of Sir William Thomson” Nature Vol. IV (Aug 3, 1871) p. 268
28 Palmieri, Luigi (1881). “La riga dell’Helium apparsa in una recente sublimazione
vesuviana” Rendiconto dell’Accademia delle Scienze Fisiche e Matematiche (Naples, Italy). 20:
223. (translated in Wikipedia “helium”)


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