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Miracle Tableau: Knock, Ireland, 1879

Investigative Files

Joe Nickell

Skeptical Inquirer Volume 41.2, March/April 2017

In January 2015, I acquired for my collection a rare Currier and Ives print—an original hand-colored lithograph (Figure 1)—depicting a supposedly miraculous occurrence at Knock, Ireland, in 1879. I had written about this event previously (Nickell 1993, 175–176), but I now decided to see if the apparitional experience could be explained in more detail.

The Event

The caption of the Currier and Ives print (dating from 1879–18861) reads as follows:


On the evening of August 21st 1879 on the outer gable wall of the Sacristy of the Catholic Church in the Village of Knock, County Mayo, Ireland, was seen an extraordinary light in the midst of which appeared the Blessed Virgin, St. Joseph and St. John the Evangelist. Behind them an Altar on which stood a Lamb and above it the Crucifix with the figure of our Lord upon it. The people soon gathered at the spot gazing rapturously on the Heavenly Vision. And crowds now visit the scene of the wonderful apparition bringing many lame and blind who by touching the structure have been miraculously cured and restored to sight.

Unlike the usual apparitions reported by lone “visionaries” (typically persons with fantasy-prone personalities [Nickell 2013, 281–282]), in which the inner vision is described to others who did not see it, the occurrence at Knock was quite different, having multiple viewers. It did, however, begin with a single witness, a young woman named Margaret Beirne who was making her daily visit to lock the doors of the village church. About 7 pm, she noticed a strange brightness that illuminated the top of the church. She gave it little thought, but half an hour later another woman, Mary McLaughlin, had a profound experience. Passing by, she saw within the glow—seeming to emanate from the church’s southern gable—the “tableau” of holy figures already described; however, the figures were standing on the left, not as depicted in the lithograph.

Figure 1. “Our Lady of Knock,” a hand-colored lithograph by Courier and Ives depicting a scene that “miraculously” appeared on a church wall at Knock, Ireland, in 1879. (Author’s collection)

There are serious discrepancies in what the fifteen or so witnesses did actually see. Some mentioned a cross or crucifix while others specifically insisted they had not seen this. Likewise, at least one witness did not see a lamb, and two boys alone saw flying angels. One figure—although described by some as a bishop wearing a miter—was seen, or later interpreted, as St. John the Evangelist. Nevertheless, there was general agreement as to the scene, but it was essentially the same as depicted in various holy pictures and a stained glass window in the nearby village of Ballyhaunis. Such images may well have influenced the perceptions of witnesses as well as their later memories.

Reportedly, while an inquiry was being conducted into the first occurrence, “another apparition took place on January 6, 1880, followed by two more on February 10th and 12th of the same year.” Again, there were multiple witnesses and “The visions remained identical” each time (Aradi 1954, 101). A different view comes from another source (“Knock” 2015): “Apparitions of lights on the gable and even of the Virgin herself were seen after the vision but the church dismissed those stories.” There is no official record of the later phenomena (“Knock Shrine” 2015).

In any event, in the original mysterious tableau according to Margaret Beirne’s sister Mary, the Virgin was “life-size, the others apparently not so big or not so tall” (qtd. in Mullen 1998, 99). For some two hours the faithful watched the “apparition” in the falling rain, while the figures in the tableau remained unmoving and unspeaking (except, apparently for the one early sudden movement reported by two of the earliest witnesses [Rogo 1982, 218]). Indeed, Mary McLaughlin first thought the three figures were actual churchyard statues (perhaps, she thought mistakenly, replacements for those destroyed recently in a storm) (Mullen 1998, 99). One skeptic huffed that the experiencers “saw an apparition of statues!” (“Knock” 2015).

Apparition vs. Illusion

The ability to see pictures in random forms—as in clouds, tea leaves, and inkblots—is known as pareidolia; the images themselves are called simulacra. Some publicized examples I have made pilgrimages to to examine include the face of Jesus in the skillet burns of a tortilla; the figure of Mary in the iridescent stain on a window (caused by water deposits from a sprinkler); the Madonna cradling the infant Jesus, in another window stain; and Jesus emerging from his tomb in a church’s patterned marble. (See my “Rorschach Icons,” Nickell 2007, 18–26.)

At Knock, the various elements—the multiple viewers, the unusual light, the immobility of the scene, the mismatched size of the figures, and the duration of the phenomenon—all suggest some type of optical illusion, probably involving pareidolia. Such illusions are known. In August 1986, for example, a Catholic woman reported seeing an illuminated image of Jesus, with his hand on the shoulder of a young boy, on a Fostoria, Ohio, soybean oil tank. Other believers saw the image, while nonbelievers tended to see nothing. As spokesman for the tank’s owner, the Archer Daniel Midland Company, explained the image as “a combination of lighting, rust spots, fog, and people’s imaginations” (qtd. in Nickell 1993, 36).

Another illusion occurred at Santa Fe Springs, California, in 1981. A couple saw on their garage door in the evenings the head of Christ crowned with thorns surmounting a cross. As it turned out, the effect was caused by the combined shadows of a real estate sign and a nearby bush, which were cast by a pair of street lamps (Nickell 1993, 28).


Many have tried to explain the phenomenon at Knock—first, of course, as supernatural. But like other such claims, it is based on a logical fallacy called an argument from ignorance: “No one can explain it, therefore, it must have been a miracle,” they say. In fact, one cannot draw a conclusion from a lack of knowledge. Substitute “X-force” for “miracle,” and we see what a non-explanation it is.

Skeptics have not done so well either. One proposal is that it was pure suggestion: Mary Beirne, who saw a strange light, was the first to “identify” the figure of the Virgin Mary and quickly adopted a leadership position; she then influenced the others. In part, this no doubt happened, but it is unlikely as a complete explanation. Others have suggested a hoax, that, for instance, luminous-painted canvas cutouts were secretly hung on the wall; however, this can hardly be taken seriously. Another suggestion has been the use of a magic lantern, say hidden in a nearby school; or perhaps an altar-shaped box was temporarily attached to the wall itself, which “concealed the magic lantern and mirrors required to make the image” (“Knock” 2015). But could there be a simpler, natural explanation?

We have already considered some clues as to what might have happened. There are more. The gable wall was enveloped in the “eerie light” during the entire event, while rain continued to fall. Moreover, “The whole tableau seemed to stand out from the gable wall and to float about a foot and a half above the ground.” Yet the apparitions, continues Rogo, “were obviously ephemeral” (1982, 219). One old woman said she went up “to kiss, as I thought the feet of the Blessed Virgin; but I felt nothing in the embrace but the wall, and I wondered why I could not feel with my hands the figures I had so plainly and so distinctly seen” (quoted in “Knock Shrine” 2015).

The Mysterious Light

The light was first noticed illuminating the top of the church, and then seen to emanate from the south gable (Rogo 1982, 218). It was not uniform, since even a monochromatic (one-color) picture must have tonal values (lights and darks) to form shapes. (Think of an ordinary black-and-white or sepia-tone photograph.) Mary Beirne first said the Virgin’s cloak was “of white color” and the crown rather yellow (Mullen 1989, 99; “Knock” 2015). Whether the light “flickered” (Aradi 1954, 101) or portions “glimmered” (Rogo 1982, 218) or they did not (“Knock Shrine” 2015) is contradictorily stated. Whether there might have been shadow effects is also unknown. Mary Beirne saw stars that were “gold” (i.e., a deeper yellow) around the Lamb. “She admitted that the stars seemed to be caused by reflection” (“Knock” 2015; emphasis added).

But what was the source of the light? I consulted my colleague James McGaha, director of the Grasslands Observatory in Arizona. He made a computer recreation of the sky at the place, date, and time2 of the “miracle,” and discovered that the evening sun, coming from due west (270˚) was above the horizon for the duration of the miracle. Moreover, not far from the church had been a school (shown in an 1879 survey of the area [“Knock” 2015]); it stood to the southeast, its eastern wall angled toward the church’s south gable.

What is suggested is a natural version of a magic-lantern effect. Indeed, with the sun as a light source, an illusion was created with “smoke and mirrors”—or rather, rainy mist and reflective windows.3 Such effects are documented. For example, diffuse reflections from windows, projected onto the wall of a nearby building, have been photographed. (See Min­naert 1993, 17.) These odd shapes could produce the requisite pareidolia (pictures-in-randomness) effects in susceptible individuals, especially those who were motivated to see something “miraculous” and were familiar with similar holy pictures.

McGaha stresses that while other scenarios are conceivable, the conditions that were apparently operative at Knock were ideal for producing such an optical illusion. His calculations show that “The angular relationship between the school wall and the chapel wall perfectly matches an angle of incidence to an angle of reflection, in relation to the azimuth of the sun.”

Although rain clouds overhead would have darkened the sky, the setting sun could—and rather obviously did—serve as the light source. And everyone has seen strange lighting effects caused by the sun—sometimes shining while rain is falling. Rainy mist in front of the church wall probably played a significant role in the tableau illusion. The reflected images could have been projected in part onto such diaphanous mist, helping create the illusion that—as reported—the “figures” stood away from the wall, seeming “always just beyond reach” (Mullen 1998, 100), yet proving entirely without substance when one tried to grasp them.

The mystery light lasted—like the sun’s light—from before the time the first witnesses noticed it until after everyone had left. They went to see about an old woman who, having been left alone, got out of her sickbed to try to see the vision and collapsed. After a few returned to the site some ten or fifteen minutes later, the lighted vision had vanished (“Knock” 2015). So, of course, had the sun.

The Healings

An enterprising archdeacon worked the following morning to bottle rainwater that had flowed down the gable and use it to create holy water with supposedly curative powers (“Knock” 2015). People came to be healed, and “Knock soon became celebrated as one of the great Marian shrines” (Aradi 1954, 102). Unfortunately, the zealous were so intent on breaking pieces of cement from the church wall—for their supposedly curative power—that the wall became in danger of collapsing (“Knock” 2015).

As to the “miracle” cures at Knock, these are typically based, again, on the illogic of arguing from ignorance. Moreover, healings may be attributed—like such claims elsewhere—to mis­diagnosis, psychosomatic conditions, spontaneous remission, prior medical treatment, the body’s own healing power, and other effects, including exaggeration and even outright hoaxing.

With tragic irony, some people have been harmed rather than healed at Knock. Certain of the faithful were apparently persuaded by the predictions of self-proclaimed mystic Joe Coleman from Dublin that there would be a Miracle of the Sun like that reported in Fatima, Portugal, in 1917. In 2009, many people reported observing such phenomena at Knock, but unfortunately there was a correlation with a spike in cases of retinal damage. As an ophthalmologist explained, the “dancing” sun and other effects were merely visual disturbances due to staring at the sun, which can cause reduced sight and a condition called “metamorphopsia,” or distorted vision (“Knock Shrine” 2015; Taber’s 2001, 1286; Nickell 1993, 176–181). It may be wondered, then, whether any miracle has ever occurred at Knock.


Thanks to James McGaha for his expert analysis of the conditions at Knock. Thanks also to Melissa Braun and CFI Libraries Director Tim Binga.


  1. From 1876–1886, Currier and Ives were located at the address—115 Nassau St.—given on the print (Kovel and Kovel 1973, 242).
  2. The times given in the account were local time, here assumed to be one hour after that of Greenwich mean solar time.
  3. We infer the likely presence of windows in the long sides of the school building. If they were not present, we would still postulate the sun obliquely hitting the church wall directly, with other scenarios for the random, diffuse forms.


Joe Nickell

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Joe Nickell, Ph.D., is Senior Research Fellow of the Committee for Skeptical Inquiry (CSI) and "Investigative Files" Columnist for Skeptical Inquirer. A former stage magician, private investigator, and teacher, he is author of numerous books, including Inquest on the Shroud of Turin (1998), Pen, Ink and Evidence (2003), Unsolved History (2005) and Adventures in Paranormal Investigation (2007). He has appeared in many television documentaries and has been profiled in The New Yorker and on NBC's Today Show. His personal website is at