Folios 17-21: The surgeon's suggestions for overcoming some of the symptoms and dangers...

Folios 17-21: The surgeon's suggestions for overcoming some of the symptoms and dangers faced by divers. Giddiness does not seem to arise from want of air alone but rather from nervousness, which would follow on from a lack of air, or from a predisposition on the part of the diver, increasing respiration. The great danger from giddiness is that the diver would fall and water enter his helmet, if it is not attached to his suit, or the helmet might 'become so deranged that in the man's senseless state he would be unable to right it'. The surgeon suggests a strong rubber bag attached to tubes of compressed air could be used to right the diver or bring him to the surface, the tubes of compressed air doubling as weights. The pain sometimes experienced in the ears, forehead and over the eyes arises from unequal pressure between the air being supplied to the diver and his own internal pressure. This may also account for the small ruptures of blood vessels in the nose and throat. Over exertion or excitement leads to increased respiration and if the air supply is insufficient and the diver wet or damp, this may account for the intercostal rheumatism. The surgeon provides some arguments to prove these statements and suggests improvements to the air pump to regulate the pressure of the air supplied to the diver. These include the use of gears and a flywheel, to lessen the effort required by those working the pumps, and pumping the air through a sealed reservoir of water fitted with pressure gauges as a means of measuring and regulating the pressure.

Folio 21: Insert showing a diagram of the surgeon's proposed design for an improved air pump, illustrating the cranks, gears, flywheel and water reservoir.

Folios 22-25: Consideration of the dangers faced by divers, beyond those from accidents and imperfect equipment. All divers would be subject to catarrh or rheumatism, depending on their constitutions. The surgeon lists a number of diseases which should prevent a man from diving, including, tubercular lungs, asthma, diseased hearts, and those of plethoric habit or prone to nervousness. Men with healthy and capacious lungs, strong muscular development, good nerves and presence of mind 'need have nothing to fear beyond the possibility of accident by derangement of the diving gear'. The surgeon discusses the dangers facing a man of full plethoric habit, liable to apoplexy, the dangers facing men with tubercular lungs, asthma or bronchial disease, and finally those facing a man with a diseased heart.

Folios 25-26: A story related by Mr Revell, an engineer, of an accident in a diving bell being used in repair work on Westminster Bridge [in 1831]. The man at work in the bell apparently had his eyebrows and whiskers singed off when the 'foul air' in the bell was ignited by the Davy lamp he was using. The surgeon initially understood the air had been ignited by compression and quotes the story as an example of an accident that could be avoided by using his improved air pump.

Folio 26: Comments on coals recovered from the Royal George. They were found in the bottom of the wreck and required several explosions to clear them, the largest of 150lbs. They were found to be of very good quality and burned well.