# Total volume of relics of the True Cross

In this thread, I posted a brief response to the oft-heard claim that if all the relics of the True Cross were collected together, one would have enough wood for a giant cross/dozens of crosses/a forest of crosses, or whatever superlative amount of wood you desire. I’ve never seen any positive evidence in favor of this claim, but on the contrary, in 1870 a man named Rohault de Fleury sat down and calculated all known existing pieces of the True Cross, as well as pieces whose existence was recorded but were no longer around, and published his results under the title Memoire sur les instruments de la Passion. The Catholic Encyclopedia’s article on the subject has this to say on his conclusions:

Has anybody ever been able to debunk de Fleury’s research, or is this bit about the magically multiplying Cross wood just another anti-Catholic legend?

I am curious how M. Rohault de Fleury determined the volume of the cross.

According to the article, he assumed a cross of 3 - 4 metres in height and 2 metres across. The vertical portion may have been shorter, but this would necessitate putting Christ nearly at ground level, instead of raising Him up for display. Assuming Christ had normally proportioned arms, 2 metres for the crossbeam is a reasonable guess, especially considering that the cross probably would have been ready-made rather than custom-fitted. The wood would have had to have been a certain thickness in order to support the weight of an adult man. From there it’s just a matter of figuring out what volume of wood would have been necessary for a cross like that.

Thanks. Fr. Debosier had a relic of a Saint, seal in wax and certified by an office of the Catholic Church. I presume that certified relics were counted in calculating the volume, rather than pieces such as those sold by the Pardoner in the Canterbury Tales.

Well, the quote from the Catholic Encycopedia suggests that he assumed a weight for the cross and assumed that it was made of pine. From these two assumptions, and given information about the typical density of pine, it is not difficult to compute the approximate volume of the cross.

You could criticise the assumptions. Perhaps Roman crosses are known to have been made from some wood other than pine, at any rate in Palestine, or there is good reason to think they were? Perhaps 75kg is absurdly large for a cross? I have no idea. But in principle it seems to me that it shouldn’t be difficult to make reasonable assumptions or guesses about the dimensions of a cross used in a Roman crucifixion in first-century Palestine. On Rohault’s figures, even if his assumptions were out by a factor of 10, the total volume of the relics is still significantly less than the estimated volume of the cross.

One of the Catholic churches here in Sydney has a relic of the True Cross, similarly sealed in wax and certified. It is venerated each year on Good Friday and 14 September (the feast of the Exaltation of the Holy Cross).

If we assume the cross recovered by St. Helena to have been the original Cross of Christ (and I have no idea how reasonable the claim that it was may be or not be), it doesn’t sound too difficult to trace the transmission of relics removed from it, allowing a little more tolerance of “My grandfather told me” claims than would be permissible in a more stringent study.

It is my firm belief that if Jehovah God wanted for man to have the true cross and/or the fragments of it in the hands of men today He would have made sure that they would have more than adequate authentication.

Since there is no such authentication, such parts are nothing more nor less than peices of wood. Even the location of the tomb is in doubt for the same reason.

A very good reson for no authentication of the cross, holy grail, the ark, etc. is that men would worship that which they can see and touch than the Infinite God which must be worshiped in faith.

Abraham seems to have felt that way, spingears.
I’m curious what your religious background is.

To put this in some perspective, 4,000,000 cubic millimeters corresponds to a cube of about six inches on each side. So there can be little doubt that this is much smaller than the volume of the cross.

Where do they get the number? Are only certified relics counted, or do they include the Pardoner from Chaucer?

It seems to answer the question to me.
Certified relics are real, and those sold by the Pardoner are fake.
…we need a tongue in cheek smiley…

I can’t find a definitive answer on the web, but my very strong guess would be that the count extended only to certified relics, and possibly also (if they exist) to prominent and long-established relics which are widely venerated but have never been certified. I think this for two reasons:

• There would be no reliable way of identifying all the “Pardoner’s relics” ever circulated, still less of measuring their volume.

• It would have been common ground among everyone that a very large proportion of “Pardoner’s relics” were completely bogus, regardless of whether their volume exceeded the likely volume of a first-century cross.

As I understand it, the public display or reservation for public veneration of uncertified relics is now forbidden by the Catholic Church, and would have been in Rohault’s time. But the comment about “enough wood for a ship” is attributed to Erasmus, and in the much more decentralised Catholic Church of this time I doubt if the display or veneration of relics was so controlled. It’s very possible that the comment would have been true (or, at least, justifiable hyperbole) in the time of Erasmus, but not in Rohault’s time or our own.

Carnivorousplant, I know you’re speaking tongue in cheek, but the object of Rohault’s study was not to demonstrate that the relics were, indeed, fragments of the original cross, but merely to refute the assertion, still being made in Rohault’s time, that they were so numerous that the bulk of them could not possibly be relics of the original cross.