This is the penal cross. It has shortened arms, a pot and a cockerel at the base. It was'nt designed - it developed, a swift adaptation to the Penal Laws, laws that meant a priest or anyone acting in place of a priest could be killed by the state. What does it tell us? Firstly, it was designed to be hidden. The slimmed down shape allowed it to be hidden in a sleeve or a boot.
Secondly, the iconography communicates a message. At the base of the cross there is a flying or leaping cockerel and a cooking pot. Some people say the cock represents Peter, and was a reminder of the ease with which our fear will lead us to betray our Saviour. This was apt, as if a suspected priest did not swear the Oath of Allegiance (to the King of England as head of the Christian church) he would die in the most horrible way. But the more correct source is a medieval legend of Judas Iscariot, recounted by Douglas Hyde in Legends of Saint and Sinners:
After Judas tried to give the silver pieces pack to the Sanhedrin, and failed, he went home, resolved to end his life. He found his wife sitting and cooking a cockerel, and he said to her: "Rise wife and get a rope ready for me for I mean to hang myself as I deserve. But his wife said to him: "Why speakest thou like that?" Judas replied: "Know that I have unjustly betrayed my master, Jesus, to the evil-doers who have taken Him before Pilate to put Him to death; but He will rise again on the third day and then woe to us." But his wife said to him: "Speak not so and believe it not. For it is just as likely that the cock roasting on the coals will crow, as that Jesus will rise, as thou sayest." With that the cock leapt up from the pot and crowed three times.
There is the lesson the people needed in penal times - certainty of resurrection, despite appearances, despite all that seems probably or even possible. They believed the Catholic Church would win through, and it did. This is also the lesson for the present times. What will happen is what is prophesied, not what seems most likely. We see only a tiny part of the causes of anything, and even less of the affects. In this Church, which we treat as a dull and rather dubious department of state, we are actually dealing with the miraculous. As in the penal times, let us have faith.