Or again, regard your head as the top of a hollow pipe which runs straight down through your body into the earth. Meditate upon the top of your head, that is to say, upon the mouth of the drain-pipe, and then gradually ascend in your thoughts to a height of four inches above the head, and concentrate firmly on this conception. You will thus easily pass into the contemplation of non-Being, having performed the transition from elementary to complete Zen as comfortably as a workman climbs the rungs of a ladder. _Question._--Are there any signs whereby I may know that I have attained to Samādhi?[4] _Answer._--To be sure there are. Sometimes you will feel a sensation as of bugs or ants creeping over your skin; or again, it will appear to you that a cloud or mass of white cotton-wool is rising immediately behind your back. In neither case must you be discomposed or put out your hand. Sometimes it will seem as though oil were dripping down from your head and face; sometimes a light will shine from out of the ground you are sitting upon. These are all preliminary signs. Sometimes when you have been sitting for a long while and your back is aching, you will suddenly hear a sound of rapping with the fingers or a noise as of some one bumping against the door. Do not be disquieted. These are the Good Spirits of Heaven, come to warn you against sleep. Again, it may happen that you have an agreeable sense of lightness and floating; this is a good sign. Beware, however, of a _painful_ sense of lightness; for this may merely indicate flatulence. Patches of heat on the body are a sign of Fiery Samādhi. A light filling the whole room is a premonitory sign of Zen; to smell strange fragrances not known on earth is a sign of whole and utter Abstraction. Such and many more are the signs of Zen. The practicant must not heed them; for if by them he be encouraged or dismayed, all his work will be undone. _Question._--Can Zen be practised in a Buddha Shrine? _Answer._--No, indeed! Zen should be practised in a quiet room or under a tree or among tombs or sitting on the dewy earth. _Question._--Can Zen be practised by many sitting together? _Answer._--To be sure it may; but each must face his neighbour’s back. They must not sit face to face. When there are many sitting together at night, a lamp or candle may be lit; but when there are few together, it ought not to be used. _Question._--Need I wear monastic vestments at my meditations? _Answer._--Vestments? Why, you need wear no clothes at all, if so be you are alone. [4] Concentration. LATER DEVELOPMENT OF ZEN.