For a man who claimed to hate the appearance of sharp things when viewed under a microscope, Hooke spent a great deal of time honing jabs at Inquisitive Jesuits. While Daniel was up on the roof making the hole, and a rain-hatch to cover it, Hooke was safe at ground level, running up and down a gallery. Strapped into his groin was a narrow hard saddle, and projecting from the saddle a strut with a wheel on the end, geared to a clock-work dial: a pedometer of his own design, which enabled him to calculate how much distance he had covered going nowhere .The purpose – as he explained to Daniel and diverse other aghast Fellows of the R.S. – was not to get from point A to point B, but to sweat. In some way, sweating would purge his body of whatever caused his headaches, nausea, and vertigo. From time to time, he would stop and refresh himself by drinking a glass of elemental mercury. He had set up a table at one end of the gallery where he stockpiled that and several of Mons. LeFebure's fashionable medicines. There were various sorts of quills, too. Some of them he used to tickle the back of his throat and induce vomiting, others he sharpened, dipped in ink, and used to note down data from his pedometer, or to vent his spleen at Jesuits who refused to admit that the Earth revolved around the Sun, or to sketch out plans for Bedlam, or to write diatribes against Oldenburg, or simply to transact the routine business of the City Surveyor.