266 PHILOSOPHICAL TRANSACTIONS. [aNNO 166S. 



In this table he notes the greatest distance or difference to be 14 minutes; 

 and so taking the mean for the true variation, he concludes it then and there to 

 be just 1 deg. 27 min. viz. June 13, l666. 



He observed again in the same day of the next year, viz. June 13, 1667, and 

 then found the variation increased about six minutes westerly. 



From many former observations Capt. Sturmy assures, that the highest spring 

 and annual tides there are about the equinoxes, according as the moon is near 

 the full or change, before or after that time. 



J7i easy Help for decayed Sight. iV" 37, pp. 727 and 729. 



The inventor of this method was about 60 years of age, but his sight much 

 decayed ; and I seemed, says he, always to have a kind of thick smoke or mist 

 about me, and some little black balls dancing in the air about my eyes, and to 

 be in such case as if I came into a room suddenly from a long walk in a great 

 snow. I could not distinguish the faces of my acquaintance, nor men from 

 women, in rooms that wanted jio light. I could not read the great and black 

 English print in the church bibles, nor keep the plain and trodden paths in 

 fields or pastures, except I was led or guided. I received no benefit by any 

 glasses, but was in the case of those whose decay by age is greater than can be 

 helped by spectacles. The fairest prints seemed through spectacles like blind 

 prints, little black remaining. 



Being in this sad pliglit, what trifle can you think has brought me help more 

 valuable than a great sum of gold ? Truly, no other than this : I took spec- 

 tacles that had the largest circles ; taking out the glasses, I put black Spanish 

 leather taper-wise into the emptied circles, which widened enough, took in my 

 whole eye at the wider end ; and presently I saw the benefit through the lesser 

 taper-end, by reading the smallest prints, which thus seem as if they had been a 

 large and fair character. I coloured the leather on the inside with ink, to take 

 off the glittering. Finding that the smaller the remote orifice was, the fairer 

 and clearer the smallest prints appeared ; and the wider that orifice was, the 

 larger object it took in, and so required the less motion of my hand and head 

 in reading ; I therefore cut one of these tapers a little wider and shorter than 

 the other, and the wider I use for ordinary prints, and the longer and smaller 

 for smallest prints: these without any trouble I alter as is necessary. I can only 

 put the very end of my little finger into the orifice of the lesser, but the same 

 finger somewhat deeper, yet not quite up to the first joint, I can insert into the 

 orifice of the wider. Sometimes I use one eye, sometimes another, for ease by 

 the change ; for you must expect that the visual rays of both eyes will not meet 



