Magneticall aduertisements: or Diuers pertinent obseruations, and approued experiments, concerning the natures and properties of the load-stone Very pleasant for knowledge, and most needfull for practise, of trauelling, or framing of instruments fit for trauellers both by sea and land. Whereunto is anexed a breife discouerie of the idle animaduersions of Mark Ridley Dr. in Physicke, vpon a treatise entituled Magneticall aduertisements.