Monday, October 16, 2017

Water Conservation in the Pre-Muchni Days

In the Second Temple era a Kohen Gadol named Ben Katin devised a machine that was used to lower the Kiyor [laver] into a well of water each night and then raise it again in the morning. This prevented the water inside from becoming disqualified and unfit for Temple use. The Sages praised Ben Katin for this great innovation that saved the Temple wasted water and the effort of refilling the Kiyor every morning. The question is, what did they do before the Muchni was invented?

Saturday, October 14, 2017

Wall Thickness Between the Tauim Part 2

SUMMARY After seeing a first printing of Tiferes Yisrael's commentary to the Mishnah, it was necessary to come up with a new, reduced wall thickness for the tauim.

In the previous post I set out to find an early printing of Tiferes Yisrael's commentary to the Mishnah in order to resolve a question about the wall thickness between the tauim. Unfortunately, first printings of Tiferes Yisrael's commentary are not all that common and sell at auction for a small fortune.

Tuesday, October 3, 2017

Wall Thickness Between the Tauim

Very few details are provided by the Mishnah for the dimensions of the tauim (small rooms surrounding the Sanctuary Building). In the key to his Temple Diagram, Tiferes Yisrael states what he believes to be the length of the various tauim. Based on his results it is possible to make a reasonable guess as to the thickness of the walls that separated the tauim from each other.

Saturday, September 9, 2017

Keys of the Heichal Revisited

In a previous post I estimated that the Heichal Building had about 42 doors that needed keys to unlock them. A large part of this calculation assumed that the doors connecting the 38 tauim [small rooms] to each other required keys, although I could not find a direct source that this was true.

Friday, June 16, 2017

JBrick to Unveil Microscale Model of Herodian Temple at Brickworld Chicago

Some people think about Lego while they are supposed to be working, and some people think about Lego because they are working. Yitzy Kasowitz is one of those lucky individuals who is paid to design and build with Lego (once you earn a salary from it we don't call it 'playing' any more). He is a member of the Brickmania team, a company that builds and sells Lego military models. Being around all that Lego must be inspiring, because Yitzy has spun off his own company called Jbrick that designs and sells Jewish-themed Lego sets. In addition to his beautiful menorahs and Seder plates, Jbrick is about to unveil an amazing new model sure to capture the imagination of young and old alike.

Friday, June 2, 2017

Refurbished Lego® Altar (Once Again)

In honor of my Loaves and Lambs presentation I tinkered with my Lego® Altar again (since the last time). I took it apart and played with the scale of things to make it more minifig-friendly. Here is the result:

Loaves and Lambs on Shavuos Night

This year I gave my second-annual presentation "Loaves and Lambs" at Cong. Darchei Tzedek on the first night of Shavuos. This class is a virtual walkthrough of the sacrificial service performed in the Temple on Shavuos. It covers the Mussaf offerings, the Shtei Halechem (two loaves of wheat flour brought on Shavuos), and the offerings which accompany the Shtei Halechem.

Monday, May 1, 2017

Drop Me a Line

It is not every day that you see a remnant of the Temple hanging around in modern times, but today was an exception. As I was headed in to Minchah I caught sight of some workers using tools and techniques taken right out of the Temple owner's manual.

Friday, November 4, 2016

Interview in Hamodia

This past Succos, the Hamodia (one of the largest Jewish newspapers) ran a feature on my Beis Hamikdash-related work.

Sunday, October 16, 2016

Elevation of the Kohen on the Mount of Olives

The Kohen standing on the Mount of Olives had to be able to see the entrance of the Sanctuary as he sprinkled the blood of the Red Cow. The Gemara explains that to do so he would need to look over the eastern gate of the Temple Mount, because if he looked through that gate the elevations of the Temple were such that he could not see the Sanctuary entrance. It can be shown, however, that there is a very simple way to see the Sanctuary entrance by looking through the gate.

Monday, October 10, 2016

Locating the Courtyard Upon the Temple Mount

Even though Tractate Middos does contain a lot of detailed measurements for the Second Temple, one of the places where the Tanna is vague is when he describes the location of the Courtyard upon the Temple Mount. The Mishnah does not give explicit numbers but rather states that the southern area (that is, the area between the southern Temple Mount wall and the Courtyard) was larger than the eastern area, and the eastern area was larger than the northern area, and the smallest area was in the west. I looked for a simple mathematical way to calculate the range of possible locations where the Courtyard could have been placed, but I didn't find one.

Sunday, October 2, 2016

Second Temple Print Arrived from Shapeways

My print of the Pocket Size Second Temple just came in from Shapeways and it turned out even better than expected.

Sunday, September 25, 2016

Pocket Second Temple Model now on Shapeways

In order to bring my Pocket Second Temple model to people who do not have their own 3D printers, I have moved a copy of it to

Monday, September 19, 2016

Pocket Size Second Temple Model

One of the projects I have been busy working on is a digital model of the Second Temple suitable for 3D printing. My first "offering" is now available on

Wednesday, December 2, 2015

Chanukas HaLEGO® Mizbeach

When the Chashmonaim recaptured the Temple many years ago, they were horrified to discover that the Altar had been used for pagan worship. As a result, they disassembled the entire Altar and ramp and built them anew. Through a similar siyata dishmaya (although on a smaller scale - literally and figuratively) I was able to refurbish and add to my LEGO® model of the Altar just in time for Chanukah.