The True Cross

“According to pious tradition, the size of the Cross of Christ was fifteen feet in height and eight feet in length. St. Cyril of Jerusalem (444 AD) writes: “The whole world has now been filled with pieces of the wood of the Cross” (Catachesis 4:10). He makes this statement no less than three times in his lectures to the catechumens of Jerusalem. St. John Chrysostom in the same century tells us that fragments of the True Cross were kept in golden reliquaries, which men reverently wore upon their persons. In 1889 two French archaeologists, Letaille and Audollent, discovered in the district of Sétif an inscription of the year 359 in which, among other relics, is mentioned the sacred wood of the Cross. Another inscription, from Rasgunia (Cape Matifu), somewhat earlier in date than the preceding, mentions another relic of the Cross.
St. Paulinus of Nola, some years later, sent to Sulpicius Severus a fragment of the True Cross with these words: “Receive a great gift in a little [compass]; and take, in [this] almost atomic segment of a short dart, an armament [against the perils] of the present and a pledge of everlasting safety” (Epistle 31). About 455 Juvenal, Patriarch of Jerusalem, sent to Pope St. Leo a fragment of the Precious Wood (Epistle 139). Later, under St. Hilary (468 AD) and under Symmachus (514 AD) we are again told that fragments of the True Cross are enclosed in altars. About the year 500 Avitus, Bishop of Vienne, asks for a portion of the Cross from the Patriarch of Jerusalem (P.L., LIX, 236, 239).”

In the Catholic Encyclopedia, the following is written to refute the Protestant and Rationalist argument that the amount of distributed relics of the Holy Cross throughout the world could be compared to the size of a battleship:

The work of Rohault de Fleury, “Mémoire sur les instruments de la Passion” (Paris, 1870), deserves more prolonged attention; its author has sought out with great care and learning all the relics of the True Cross, drawn up a catalogue of them, and, thanks to this labour, he has succeeded in showing that, in spite of what various Protestant or Rationalistic authors have pretended, the fragments of the Cross brought together again would not only not ‘be comparable in bulk to a battleship’, but would not reach one-third that of a Cross which has been supposed to have been three or four metres in height, with transverse branch of two metres, proportions not at all abnormal (op. cit., 97-179). Here is the calculation of this savant: Supposing the Cross to have been of pine-wood, as is believed by the savants who have made a special study of the subject, and giving it a weight of about seventy-five kilograms, we find that the volume of this Cross was 178,000,000 cubic millimetres. Now the total known volume of the True Cross, according to the finding of M. Rohault de Fleury, amounts to above 4,000,000 cubic millimetres, allowing the missing part to be as big as we will, the lost parts or the parts the existence of which has been overlooked, we still find ourselves far short of 178,000,000 cubic millimetres, which should make up the True Cross.

Today the largest portion of the True Cross can be found on Mount Athos (870,760 cubic millimeters; pictured above), followed by Rome (537,587), Brussels (516,090), Venice (445,582), Ghent (436,456) and Paris (237,731)

Source: Mystagogy