Pesah Hevroni: Among the great Jewish mathematicians of the twentieth century, inventor and brilliant scholar, native of Jerusalem

The archive of Dr. Pesah Hevroni is not large, but it succinctly and accurately recounts the tragic story of one of the great Jewish mathematicians of the twentieth century, an inventor and brilliant scholar born in Jerusalem, who never quite came into his own

Photo: from Wikipedia

The archive of Dr. Pesah Hevroni is not large, but it succinctly and accurately recounts the tragic story of one of the great Jewish mathematicians of the twentieth century, an inventor and brilliant scholar born in Jerusalem, who never quite came into his own. Its scant folders of letters and documents contain – in addition to an impressive correspondence with the world’s leading mathematicians of the first half of the twentieth century – a concise account of the intellectual world of this scientist and inventor who spent most of his life in Jerusalem.

Pesah Hevroni was born to a Chassidic (Chabad) family in the Mazkeret Moshe neighborhood of Jerusalem in 1888. He attended yeshiva at Etz-Hayim and Beit Hamusar and was considered a prodigy in the world of Torah study. However, the life of this bearded, sidelock-sporting, yeshiva boy took a dramatic turn when he discovered a book on cosmography – Shvilei Derakheha – in his grandfather’s library.  Appended to this book was a booklet containing short, illustrated introductions to planary geometry, trigonometry, and other mathematical areas. Intrigued by the discovery, Hevroni set out to learn more about the subject. The first stop in this quest was Beit Hasfarim Midrash Abravanel on Chabashim Street, the earliest iteration of the National Library. He hoped to find more books on mathematics in the library in order to feed the intense curiosity that had awakened in him. However, as Yosef Yoel Rivlin tells us, the road leading to the library was not without its obstacles. He was forbidden to visit this institution, which the extremist factions to which his grandfather, R. Hayim Elazar belonged regarded as profane.

Despite the difficulties he faced, the young yeshiva boy managed to acquire a significant body of mathematical knowledge from books and independent study. The more he learned, the clearer it became to him that he needed to leave the world of Torah study and undertake secular studies, specifically in the sciences, to which he was drawn. Thus, the shy yeshiva boy found his way to the most zealous intellectual in Jerusalem at the time, Eliezer Ben Yehuda. Ben Yehuda, discerning Hevroni’s technical abilities, believed he could find him a place among the students of Boris Schatz, who had just founded the arts and crafts school of Bezalel. Hevroni’s encounters with Ben Yehuda and Schatz led to further encounters with leading figures in education in Palestine at the time, who were immediately impressed by the young man’s exceptional talent. With their help, he finished his high school studies quickly. Then, having cut off his sidelocks and shaved his beard, he was sent to study mathematics at university in Zurich, Switzerland, thanks to the assistance and encouragement of Paul Nathan. In 1914, shortly before the outbreak of the First World War, Pesah Hevroni earned the title doctor of mathematics. He was the first native of the old settlement in Palestine to earn this title.  When he informed his teachers in Zurich, who nicknamed him “the Star of the East”, that he intended to return to Jerusalem immediately, they were extremely upset and tried to deter him, but to no avail.

Despite his incisive mathematical genius, Hevroni did not manage to take his place among the faculty of the newly established Hebrew University. An exchange of letters in his archive testifies to the fact that, although he taught at the university from its first day and was actually among the founders of the institute of mathematics, the university administration persistently refused him tenure as a lecturer.  A letter sent to him by Professor Hugo Bergman of the Hebrew University, and a former director of the National Library, was intended to help him achieve his goal of tenure. However, despite a recommendation from Albert Einstein and warm words from Hugo Bergman, this was not to be. A humiliated and rejected Hevroni was forced to pursue his research outside of the only academic center in the country at the time, in conditions of abject poverty.

Hevroni’s archive contains letters from the world’s greatest mathematicians, to whom he sent his articles and studies, many of which were published in various contexts all over the world. Hevroni did not rest on his laurels but participated in founding the Israel Association for Mathematical Research, worked to further science education in the country, and nurtured many students, some of whom became important scholars.

In addition to his mathematical research, Hevroni dabbled in inventing. A letter from the manager of the Mograbi Cinema in Tel Aviv teaches us that Hevroni invented a planetarium that made use of the theater’s projectors. Towards the end of his life Hevroni also became absorbed by the idea of world peace, and even began an essay on the subject, which he entitled “Journal of Peace.” It appears that he never completed this piece, but even the excerpts preserved in his archive, written in fine pencil and beautiful script, bear testimony to the fascinating spirit of this special individual.

Pesah Hevroni passed away on 18 Adar 5723 (1963), on his seventy fifth birthday. Yosef Yoel Rivlin learned from his sister that “even in his final moments, his fingers moved over the bedcovers as if writing mathematical forms and equations, and his lips continued to move….”

Letter from Hugo Bergmann to Pesah Hevroni


Rare Images: When the Land of Israel Shook in 1927

These photographs document the powerful earthquake that led to hundreds of deaths in 1927.

On the 11th of July, 1927, Mandatory Palestine and Transjordan were struck by a powerful earthquake. The tremor measured 7.5 on the Richter scale. This was the most significant natural disaster in the region in the past century, as well as a seismological research milestone – the first earthquake in the area to be documented by scientific instruments.

Hundreds of people were killed and hundreds more were injured. Damage to property was severe. Nablus, Ramla and Lod were heavily affected. Jerusalem, Jericho, Amman and Al-Salt also suffered, on a smaller scale. In Nablus alone, more than one hundred people were killed. In Jerusalem, the Hebrew University buildings on Mount Scopus were badly damaged, including Gray Hill House, the temporary home of the Institute of Jewish Studies.

That fatal summer saw preparations for construction of the Jewish National and University Library building on Mount Scopus. At the time of the earthquake, the precursor of today’s National Library of Israel was still located in its old building at Beit Ne’eman (at the end of Habashim Street – now Bnei Brit Street in Jerusalem’s Musrara neighborhood). According to one report, the Library building was not damaged at all and the books within were also unharmed. Life in the library continued as usual. To attest to this fact, only a few days after the terrible disaster, the library staff hastened to hold a small exhibition on the subject of historic earthquakes in the region.

Naturally, on the day after the disaster, the daily newspaper, Doar Hayom, devoted its pages, above all else, to the earthquake.


“A Great Tremor in Eretz Israel – It started at seven past three – the greatest tremor in its history – felt in all of the land’s cities and villages…” The article in Doar Hayom on the day after the earthquake. Click on the image for the full edition



The National Library Presents: The Earthquake of 1837

On July 13th, alongside a feature on the damages caused to various public buildings in Jerusalem, was an announcement in the paper that the Library had put together an exhibit on the history of earthquakes in the Land of Israel.


The article in Doar Hayom was published on the 13th of July, 1927. Click on the picture for the full newspaper

This article gives us a rare glimpse into what was offered in the improvised exhibition put together by the Library staff. The majority of focus in the exhibition was on the powerful earthquake that had preceded that year’s quake – this was the famous earthquake of 1837 which mainly affected the cities of Safed and Tiberias.

What was displayed in the 1927 exhibition?

The article in Doar Hayom explained that the exhibition presented three letters sent from the Land of Israel after the 1837 earthquake. They were written by Mr. Israel Mashkelov, Mr. Aryeh Yerachmiel, and Mr. Raphael Yitzchak Alfandari.

It appears that printed versions of letters sent from the Land of Israel to members and officials of the Amsterdam Jewish community were presented at the exhibition. The original letters made a great impression on the Jews of Amsterdam at the time, and they rushed to publish them in a small, three-page booklet. The booklet was widely distributed throughout Europe and became well known in the Jewish world. In these letters the earthquake is described in great detail. They also include a list of the villages and towns that were affected by the natural disaster, as well as the number of dead and injured in each locale.

This was how one of the survivors described the disaster of 1837:

“On the 24th of Tevet, during the afternoon prayer, a great and terrible tremor rose up, and any who looked upon the land could see the shaking, and here [Jerusalem] some houses and courtyards were also damaged and the whole city was afraid, but thankfully no one was hurt. And in Nablus houses fell and all the shops and sixty people perished and not one of them was of the People of Israel thank the Lord, but in Holy Galilee, ahh! Safed and Tiberias were left in ruins…Fallen and destroyed were all the houses, and all the synagogues, the Sephardic community, the community of Hasidim and our community of Pharisees were destroyed, and no house or street or marketplace was longer visible, even the wall of Tiberias fell, a fire broke out and the Sea of Galilee flooded the city.

O that my head were (full of) waters and my eyes a fountain of tears, that I might weep day and night for the slain of the daughter of my people, for we have lost two hundred souls, and I have been sent the list of our remnant, left naked, except for those who went with me to Jerusalem and who had departed from there before…”

The article also reveals that the exhibition featured a first edition Jerusalem printing of the book Seder Avodat HaKodesh, printed after the Israel Back printing house moved its printing press from Safed to Jerusalem in the wake of the earthquake. The book deals with Kabbalistic issues and was originally written by Chaim Yosef David Azulai. The1841 edition was accompanied by an unusual introduction from the printer. Israel Back was one of the pioneers of the art of printing in the Land of Israel, and he saw fit to preface the book with a long apology. He tells of the hardships he suffered, which forced him to move his printing press from the city of Safed, which was destroyed in the earthquake, to Jerusalem.

Forward by the publisher describing the earthquake in the book Seder Avodat HaKodesh.


Back’s “apology” gives readers of the book, almost one hundred and eighty years after its writing, a firsthand account of the devastation caused by the earthquake.

“…a great tremor which the Lord inflicted upon his land and his people… And the doorposts quaked from the voice of him who called, and the holy cities of Safed and Tiberias were destroyed and twenty-one souls were struck down in one moment. O that my head were (full of) waters and my eyes a fountain of tears, that I might weep day and night for the House of Israel … And it came to pass after that tribulation, the Children of Israel were dispersed to all corners of the Land of Israel …”

The Doar Hayom article, also mentioned another book displayed in the exhibition – Ahavat Tzion by Rabbi Simcha of Volozhin – which also adds to the recorded history of the earthquake in Safed and Tiberias.

The book includes an account of the 1837 earthquake described from a tourist’s point of view:

“And the doorposts quaked from the voice of the tremor and two hundred courtyards were ruined and in each courtyard several homes, some of which fell to their foundations…and some 120 souls perished. And before the tremor one Hasid of the Land of Israel was told that great trouble would come to Safed but they did not know what it was. They arranged prayers and study as is customary in our country, but our sins were such that the verdict was not torn. And some wise scholars were found dead with their faces on their books, and the Hasid was among them. And in the morning light they found a few more people alive, but several days later the tremor returned and some twenty more were killed.”

Unfortunately, we have no documentation of the public’s reaction to the Library exhibition. However, it is likely that it aroused great interest, and it seems that its success encouraged the Library’s management to collect documentation of the more recent 1927 earthquake.

On March 5th, 1929, around a year and a half after the great earthquake of July, 1927, the following announcement appeared in Doar Hayom:


The public announcement published in March, 1929 in Doar Hayom. Click on the picture for the full newspaper


“The National and University Library is assembling a collection of valuable photographs from the earthquake of 1927. Anyone who has historical material is requested to present it to the library as a gift or for copying. It is recommended to attach to all photographs the name of the photographer, the name of the location in which the photograph was taken (city, village, street, building) and the exact date on which the photograph was taken.”

This public call was a success and the Library received an influx of very interesting photographs, creating a unique record of the damage caused by the earthquake in July, 1927.


What was captured in these rare images?

The most intriguing group of photographs is comprised of thirty-two silver prints of various sizes, which were apparently photographed with the same 6 X 9 cm camera. These photographs were taken by members of the “delegation” seen in some of the pictures. They captured the damage throughout the Land of Israel, as well as Transjordan. Members of this group (Mr. Reiser, Mr. Neumann and three members of the Badian family) traveled in their cars and documented the destruction caused by the earthquake. The captions were inscribed in Hebrew and English.

The photographs were donated to the National Library in 1929. Who were the five travelers who decided to tour the country and its surroundings in their car during the great earthquake? Unfortunately, no additional documentation beyond the names has surfaced to provide an answer to this intriguing question.

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Earthquake damage in Nablus


Earthquake damage in Lod


A picture of the photographers who toured the country in the wake of the earthquake.


Earthquake damage in the village of Reineh Village in northern Israel


Earthquake damage in the village of Reineh Village in northern Israel


A street in Tiberias that was damaged in the earthquake

Another set of photographs includes 18 silver prints of various sizes, including photographs from the cities of Jerusalem and Nablus. The backs of some of the photographs are marked with the stamp of the German-based Internationale Foto-Aagentur press agency, as well as typewritten annotations in German. Apparently, these photographs were taken by various photographers and sent to the European press through the same news agency.

​ ​

Three black and white photographs from the city of Nablus were accompanied by a poignant letter from Yeshayahu Blechman, a loyal reader of Doar Hayom:

“… I am sending you three photographs that were taken a few hours after the tremors in Nablus. The photographs were taken by the manager of the Nablus branch of Spinney’s Ltd. The picture of the British police in the car seems to me to have been taken several days after the earthquake, and in the car we can see bread that was sent from Tel Aviv …”

Spinney’s was a supermarket chain that maintained branches across the Middle East. The chain supplied most of the products to the British colonies. It is, therefore, possible to infer that the shipment of bread that arrived in Nablus (in an open truck, without any cover) was taken by a representative of this company, who ordered the shipment from the branch of Spinney’s in Tel Aviv.

Another collection of photographs was donated to the Library by one of the photographers of the American Colony. The Colony’s photographers (chief among them, Eric Matson) documented the earthquake in various places throughout the country, including Jerusalem. The complete American Colony collection is kept in the Library of Congress, including photographs from this event.




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When the Mayor of Jerusalem Begged the British: Let Me Surrender!

With the withdrawal of Turkish forces from Jerusalem, the mayor's delegation set out to surrender to the British. Over and over, the mayor attempted to hand over his surrender, but his efforts were met with confusion and rejection.

General Allenby near the Jaffa Gate, the general would dismount his horse and enter the city on foot. Photo: Eric Matson, GPO

One of the highlights of the British campaign to take the Land of Israel was more of a symbolic victory than a military triumph – the conquest of Jerusalem. The rapid advance of the British Army through the Sinai, into Gaza, and then to the outskirts of Jerusalem showed the Ottoman Empire that the military situation was all but lost. Ottoman forces in the city received an order from the high command: total withdrawal from Jerusalem was to be carried out on the 9th of December, 1917.

As Turkish troops retreated from the city in droves, Mayor Hussein al-Husayni organized an official surrender mission. The mayor passed through the city’s American Colony on foot, searching for a photographer to document the historic event. When the mayor came across the Colony photographer, Lewis Larsson, he called out to him, “I’m going to hand the city over to the English, bring the camera!” On the way, they stopped at the Italian hospital, removed a white sheet from one of the beds, and tied it to a broomstick. The white flag of surrender was prepared!

Now that everything was ready for a traditional ceremony of surrender, the only question left was – who should they actually surrender to?

Around five o’clock in the morning, the mayor’s delegation happened upon two British cooks. These men had been sent to procure eggs from a village outside of Jerusalem the previous evening, and had lost their way back to the British encampment. The mayor and his companions hastened to surrender to the two flabbergasted sergeants and presented to them, as representatives of the mighty British army, the official decree and white flag of surrender.

This unusual situation became all the more strange when the two sergeants came to their senses and refused to accept the surrender. They asked the dignitaries to postpone the affair for a few hours and to join them while they went to look for their commander. Jerusalem’s surrender to its new imperial overlords was put on hold.

As the cooks made their way to the camp, two more sergeants from a British scout patrol suddenly appeared, armed with rifles and demanding, at gunpoint, that the members of the delegation identify themselves. The mayor kept his cool and tried, for the second time, to surrender to two minor representatives of the great British military. The sergeants refused the delegation once again, demanding that they wait until their commander arrived. However, being proper English gentlemen, they did agree to have their picture taken with the city’s honorable dignitaries.

The mayor’s delegation with the two scouts who refused to accept their surrender, from the Library of Congress archives

Several hours later, a Colonel Watson arrived and was presented to the mayor and his party. Watson considered himself to be of sufficient rank and status, and he agreed to accept the dignitary’s letter of surrender. At the end of the hurried ceremony, the colonel turned to the photographer and asked him, “Where can I have a cup of tea?” From there, the group continued to Shaare Zedek Hospital to celebrate the city’s surrender over tea and biscuits.

The next day Larsson the photographer brought the pictures of Watson’s formal ceremony to Major General John Shea’s headquarters. Recognizing the importance of the historical occasion, Larsson asked the general about the proper way to transfer the photographs to London. “What pictures?” the general asked in incredulity. “Are you referring to the photographs from the ceremony in which I read the manifesto on the steps of the Tower of David?”

When General Shea heard about the events of the previous day from the photographer who had documented them, he was furious at Colonel Watson, who had accepted the surrender of the city on behalf of General Edmund Allenby. He ordered the photographer to destroy the pictures of Watson’s “unofficial” ceremony. He insisted that the “real ceremony of surrender” was the one that had taken place on the steps of the Tower of David.

Two days after Mayor al-Husayni’s surrender, the commander of the British Empire’s Egyptian Expeditionary Force, the officer now in charge of the entire region, arrived in Jerusalem. At the entrance to Jaffa Gate, General Edmund Henry Hynman Allenby descended from his horse and entered the city on foot, lest he be seen as a patronizing and cruel conqueror, looking down at the inhabitants from atop his steed.

General Allenby near the Jaffa Gate, the general would dismount his horse and enter the city on foot. Photo: Eric Matson, GPO

Allenby abruptly nullified all previous surrender ceremonies and demanded that a third (or fourth, depending on how one counts) surrender ceremony be organized. Mayor al-Husayni was not present at this final ceremony on the pretext that he had contracted pneumonia on the day of the long surrender, two days prior.

General Allenby accompanied by officers from the armies of three nations (the United States, France, and Italy) entered Jerusalem via the Jaffa Gate. The Prizker Family National Photography Collection at the National Library of Israel

Thus, in the absence of the mayor, the official ceremony of surrender was held in the city of Jerusalem. It was attended by General Allenby, leaders of the city’s various communities, and several thousand residents who came to see their new rulers. A few weeks later, Mayor Hussein al-Husayni died of pneumonia.

The ceremony of Jerusalem’s surrender to General Allenby. The Prizker Family National Photography Collection at the National Library of Israel


The quotations above are taken from the article – The Battle over the Photographs of Surrender by Dov Gavish, published in the book Jerusalem 5678, 1917/8: Destruction, Miracle and Redemption (Hebrew)

‘הקרב על תצלומי הכניעה מאת דב גביש, ‘ירושלים תרע”ח, 1917/8: חורבן נס וגאולה



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Unicorns in the Holy Land?

Is it possible that the unicorn, that graceful and noble mythological creature, in fact originates from the Land of Israel?


For thousands of years, unicorns have intrigued the human soul. Generations of writers have described a large beast with a single horn, its features varying from one account to the next. Great myths were attributed to it and are still a part of today’s popular culture. Unicorns didn’t always appear as we imagine them today – a white horse bearing a large horn. At times it resembled more the image of a goat, donkey or even a combination of different animals, sometimes there were no horses involved at all. Depictions of unicorns come from all over the world; Chinese figurines can be found, for example, in the shape of single-horned dragons. Stories about unicorns were told everywhere, though somehow, the beasts were always said to come from a far away place.

Could it be that the myth of the unicorn originally emerged here, in Israel? That is one assumption. Ancient descriptions point to locations such as the Indus Valley in India; others claim that the beast’s depictions are based on the African rhinoceros or Narwhals from the Arctic Ocean. In addition, a common theory ties the stories of unicorns to an animal whose natural habitat is the Negev desert in Southern Israel, its name appearing for the first time in the Bible – the re’em. We know it today as the oryx.

A white oryx (re’em) in Israel’s Arava desert. Photo: Shlomi Chetrit

The re’em/oryx, is a type of large antelope; there are several different species of oryx living around Africa and the Middle East. The kind found in Israel and the surrounding Arab countries is the white oryx, or the Arabian oryx, its coat mostly white, with two long, straight horns on its head.

Wait a minute – two horns? Here we are, discussing an elusive, mysterious creature whose name clearly suggests a single, majestic horn, and now you tell me we’re dealing with a plain old antelope?

Bear with us for a moment please…

It may be that the confusion surrounding the re’em and its identification with the unicorn first appeared due to a translation issue: Ancient translations of the Bible into Greek (the Septuagint) and Latin (the Vulgate) interpreted the Hebrew word re’em as ‘unicorn’ (monoceros/unicornis). The re’em is mentioned in many verses in the Bible; it was associated with virtues of strength and power; it is also one of the symbols of the Tribe of Ephraim. Some Hebrew sources, however, have suggested that the Tahash mentioned in the Bible, often translated as “badger”, was in fact the unicorn we have in mind.

An illustration of a unicorn in the 14th century Duke of Sussex Bible, held in the British Library

Yet it could be that the link between the re’em and the mythical unicorn is based on actual sightings. The Holy Land was always a desired destination for pilgrims and tourists who came to walk the paths traveled by Jesus of Nazareth. Some of the travelers, among them various monks and artists, described their arduous journeys in vivid detail, including accounts of the region’s geography, as well as its flora and fauna. Some of these accounts, primarily from the early modern period, contain depictions, occasionally illustrated, of a mysterious unicorn.

An illustration of a unicorn, Gershom Bar Eliezer Pentateuch, 14th century. The Bodleian Library at the University of Oxford

For example, in one of the first books (as opposed to manuscripts) containing an account of a journey to the Holy Land, composed by the German traveler Bernhard von Breydenbach, we find an illustration of various animals he spotted during his travels. The book was written between 1484-1486. Von Breydenbach traveled from Venice to Jaffa, making his way to Jerusalem before later heading south to the Sinai desert. The illustration shows a number of exotic animals including a camel, a crocodile, a goat, a salamander and – a unicorn. Von Breydenbach wrote that he got a brief glimpse of one in Sinai. Could this have been the re’em, whose natural habitat is the Negev and the surrounding desert areas?

An illustration from Bernard von Breydenbach’s book, 15th century. The Eran Laor Cartographic Collection at the National Library of Israel

Felix Fabri, a Dominican friar who traveled to the Land of Israel around the same time, also left a detailed description of a unicorn. Fabri’s sighting also occurred in the Sinai desert, with the friar describing a noble animal, with an energy like no other, its horn over one meter long. He quoted locals who told him it was nearly impossible to hunt the unicorn, though he noted that earlier writers expressed the belief that the wild beast could be tamed by the hand of a virgin.

During the 16th century, the Franciscan friar Noe Bianco made his own pilgrimage and, naturally, wrote a travel journal describing his journey. He too retraced the pilgrims’ path mentioned above, beginning in Venice before traveling to Jerusalem and then Mount Sinai. In his book we find an engraving similar to the one in Von Breydenbach’s book, depicting exotic animals spotted along the way. The engraving features an illustration of a baboon next to a unicorn, which in this case resembles a large goat.

An image from Noe Bianco’s book, Viaggio da Venetia al Santo Sepolcro, et al monte Sina, 16th century

What might explain these sightings? According to one theory, the re’em‘s long, straight horns may appear as a single horn if the animal is viewed from the side. A viewer who is only able to get a quick glimpse from such an angle might mistake the oryx for a large horse with a single horn. Nonetheless, the locals who hunted the beast were clearly aware it possessed two horns. Therefore, another theory suggests that the stories are based on re’ems who lost one of their horns at some point, as these protrusions never grow back.

What, then, were the unicorns that appeared in the records of travelers to the Land Israel? Were they indeed the large, noble re’ems, who nonchalantly chewed the leaves of desert shrubs as they stared at the excited onlookers? Did the travelers truly encounter mythical horses who surrendered to the touch of a young virgin? Or are these all figments of imagination and campfire legends? We will probably never know. Luckily, we can still search for unicorns today: If you wish to relive the experiences of these early European pilgrims, make your way south to the Arava desert; there you will find, at the Yotvata Hai-Bar Nature Reserve, approximately 200 oryxes who have been reintroduced to nature as part of a local reacclimation project. We prefer to call them ‘unicorns’.


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