The operator kneels, straddles one or both of the patient’s thighs, and faces his head.  Locating the lowest rib, the operator, with his thumbs nearly parallel to his fingers, places his hands so that the little finger curls over the twelfth rib.  If the hands are on the pelvic bones the object of the work is defeated; hence the bones of the pelvis are first located in order to avoid them.  The hands must be free from the pelvis and resting on the lowest rib.  By operating on the bare back it is easier to locate the lower ribs and avoid the pelvis.  The nearer the ends of the ribs the hands are placed without sliding off the better.  The hands are thus removed from the spine, the fingers being nearly out of sight.

The fingers help some, but the chief pressure is exerted by the heels (thenar and hypothenar eminences) of the hands, with the weight coming straight from the shoulders.  It is a waste of energy to bend the arms at the elbows and shove in from the sides, because the muscles of the back are stronger than the muscles of the arms.

The operator’s arms are held straight, and his weight is brought from his shoulders by bringing his body and shoulders forward.  This weight is gradually increased until at the end of the three seconds of vertical pressure upon the lower ribs of the patient the force is felt to be heavy enough to compress the parts; then the weight is suddenly removed.  If there is danger of not returning the hands to the right position again, they can remain lightly in place; but it is usually better to remove the hands entirely.  If the operator is light and the patient an overweight adult, he can utilize over 80 per cent of his weight by raising his knees from the ground and supporting himself entirely on his toes and the heels of his hands, the latter properly placed on the ends of the floating ribs of the patient.  In this manner he can work as effectively as a heavy man.

A light feather or a piece of absorbent cotton drawn out thin and held near the nose by some one will indicate by its movements whether or not there is a current of air going and coming with each forced expiration and spontaneous inspiration.

The natural rate of breathing is 12 to 15 times per minute.  The rate of operation should not exceed this.  The lungs must be thoroughly emptied by three seconds of pressure, then refilling takes care of itself.  Pressure and release of pressure—­one complete respiration—­occupies about five seconds.  If the operator is alone, he can be guided in each act by his own deep, regular respiration or by counting or by his watch lying by his side.  If comrades are present, he can be advised by them.

The duration of the efforts as artificial respiration should ordinarily exceed an hour; indefinitely longer if there are any evidences of returning animation, by way of breathing, speaking, or movements.  There are liable to be evidences of life within 25 minutes in patients who will recover from electric shock, but where there is doubt the patient should be given the benefit of the doubt.  In drowning, especially, recoveries are on record after two hours or more of unconsciousness; hence, the Schaefer method, being easy of operation, is more likely to be persisted in.