Monday, October 5, 2015

Building a Roman Arch

We have been studying Ancient Rome using mostly lessons, suggested literature, and suggested extension activities from The Story of the World.  Last week we built a Roman road, this week we wanted to build a Roman arch. Although Roman Arch block sets are sold by many Montessori companies it's an extra and therefore not in many of the albums.  I had an strong idea of how I wanted to present this, but wanted some support for the technical details.  The only album that I had with a presentation was the Physical Science album from Mid-America.  However, the method for presenting was to demonstrate assembly and then let the child do it.  This was the opposite of the approach I had planned.  I didn't want to show them how to do it.  I wanted them to figure it out like an ancient Roman (without the heavy lifting) and discover the compression and tension forces on their own.   Fortunately I found some free lesson plans online, from a non-Montessori source, that were exactly what I had in mind.  You can find them here.  I  downloaded the "Rome Lesson Plans" file and presented specific sections. If you are not doing Story of the World you might want to present all parts of the lesson.  We already had covered some sections in our previous work.  I can't give you a script here for what I did without plagiarizing the  lesson plans.  But, I can point you to the exact sections we did.

We bought our the Haba Roman Arch Building Block Set.   However, if you don't want to buy one or want to save the money or just want to give your children the extra experience, the lesson plans I linked provide instructions on page 5 for making your own blocks using plaster and ice cube trays.  

The lesson plans are divided into five lessons.  We skipped Lesson 1 Who are the Romans?, Lesson 2 What Did They Invent?, and Lesson 4 the Civilization Game.  

The lesson is structured around The Engineering Method.  I provided the kids with a laminated printout of the color chart of the Engineering method from page 12.  Then, I started reading the script starting with item two on page four and continuing through item five.  It presents the problem as a story.  A Roman Emperor has conquered a new region and need to connect each city to a water source.  

Define the Problem:  How do you move water from a water source to a city?
Do Background Research (about the geography and materials available):  We discussed what we had already learned.
Specify Requirements:  I presented the boys with the basic and advanced arch requirement pages from page 13.  They decided to satisfy the basic requirements first and move on to the advanced requirements if successful.

The fourth element in this lesson is to show the children a model or photograph of the arch and allow students a few minutes to observe the arch and ask questions. We revisited the applicable pages from City: A Story of Roman Planning and Construction.  

Then, I presented the boys with the building challenge.  We put the images away and I gave them all of the pieces they needed in a large basket.  I did not give them the instructions from the Haba kit. They spent about an hour piecing these together in different ways.

Finally, they had an arch that met the most basic requirements: 
  • The arch must stand by itself.
  • The opening must be rounded.
  • The arch must be constructed using at least two "stones."
  • The opening must be tall and wide enough for a cup to fit through.

As you can see, this doesn't look like the picture on the cover of the box.  It also will not meet the advanced arch requirements which means the arch must withstand a certain amout of weight placed directly on top of the arch.

The boys decided to stop at that point for the day.  I bought them some Roman citizen and army figures that they enjoyed (these and these).  They are looking forward to building the arch outside near their Roman road and adding the figures.  They have been working on constructing some other buildings to go along with, mostly from popsicle sticks, just for fun.  

On a second day,  Kal-El wanted to meet the advanced requirements.  I presented "Lesson 3" from the lesson plans.  On page 6 we did sections 1-6, which included reexamining pictures, learning the parts of the arch, and demonstrating compression forces with a circle sit before attempting to build a more stable arch.   We used the graphic of the compression forces from page 14.  I was was surprised that I couldn't find a set of three-part cards to buy for the Roman arch.  So I made my own set of cards and a control booklet.  Terminology covered includes:  keystone, voussoir, springer, impost, plinth, pier, abutment, crown, haunch, spandrel, span, and rise.

Kal-El spent a lot of time building and building the arch and testing it with various weights.  The lesson plans suggested that the weight be determined by the class.  This was a great idea and I personally couldn't think of what we might use for this.  I didn't need to worry about it.  Kal-El decided that the bead materials, specifically the cubes, were great weights.  He tested each arch model starting with the one cube and then testing each next larger cube in turn until the arch collapsed so that he could measure the success of various models.  I never would have thought of that.  There are "testing your arch" pages in the "student journal" file on the lesson plan website but I hadn't printed them and Kal-El was just fine recording this on his own.  He never was able to create and arch that would hold anything heavier than the five cube.  So, on day three he asked for the instruction manual.

Here is the arch as built per the instructions.  There are other models available out there.  I chose this one because it was the same as on the Montessori sites, but I saw some that had better pier and abutment options.

There you have it!  If anyone else has good Montessori-friendly resources for this lesson, please share them in the comments!


  1. Soo cool! Your pics are just great too! They look so grown up! I always say that. :)
    We are so not there, still struggling to remember what a multiplicand, a noun, and a 1/4 are. BUT I will file this away for later! Thanks!

    Totally off topic, what are the pictures you have hanging on the wall behind the boys?

    1. Those are flashcards from our Spanish program. Those happen to be some weather expressions and some months of the year. I use them initially to give three period lessons (like in primary) to learn the words. Later, I hang them up and the boys take turns following my commands with them. For example, "Pon 'Septiembre' en la cabeza" (Put 'September' on your head) or "Salta con 'hace viento'." (Jump with 'it's windy.').

  2. Awesome!

    In your own searching around, did you happen to come across a book or possibly a set of books about architecture in various cultures? Or perhaps they were short books about specific ancient cultures that covered a variety of topics....

    There are two sets I am thinking of - we own one set that is appropriate reading for upper elementary; but the other one is "simpler" reading (lower elementary) - and I can't seem to find it again (saw it at the library - but maybe I made it up!) ;)

    1. I think you might mean either a bunch of David Macaulay books or one specific David Macaulay book. He has a bunch of books like the one I linked in the post, City (romans) but also "Mosque", "Cathedral", "Pyramid", "Mill", etc., But there is also one specific book that covers many of these at once "Building Big." He also has a cool book about UNbuilding the Empire State Building. I just bought a lot of almost all of his books on Ebay (just came today).

  3. MBT: Any chance you would be willing to share the 3 part card file you made for the Roman Arch? Or perhaps where you found your pictures to make them?

  4. Sort of?

    Here is the image I used:

    I printed it, whited out the words on it, photocopied it a bunch of times and hand-colored the parts red.

    Here is a link to my definitions file:

    Here is a link to my labels: