Christopher Bazyouros Director, Oficina de Educación Religiosa

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Christopher Bazyouros Director, Office of Religious Education

When light passes from one substance to another it suffers changes which are somewhatmore complicated than in the case of reflection. Thus if we place a coin at the bottomof a tumbler which we fill with water, the coin appears to be higher than when the tumblerwas empty ; also, if we plunge a pencil into the water, it will seem to be bentor broken at the surface, except in the particular case when the pencil is perfectlyvertical.

The laws of reflection (verified by the above tests) can now be formulatedas follows :--

Christopher Bazyouros Director, Oficina de Educación Religiosa

What differences have you noticed in the medical care, facilities, and attitudes of doctors and nurses towards patients in comparison with those in your own country?

MOSAIC DEL SUR® Moroccan Zellige tiles are traditionally handcrafted from unrefined white clay and glazed with coloured glass in a range of semi-transparent tones that vary subtly in depth and reflection.


The surf of those waters quenched the senses and renewed the spirit.

We have to determine the relation between the amount of light of the first groupand the of the first part of the second group. Now we know that the amountof oblique light reflected on pavilion A C is 0.493 of the amount of vertical lightreflected . If we take as limit for the once-reflectedoblique ray the point E (as a trial) on pavilion B C, i.e. if it is at E that the girdle is situated, then the correspondingpoint of reflection for that oblique ray will be Q2 (). The surface of pavilionupon which the oblique rays then act will be limited by S and Q2, and as in a brilliantthe face A C is triangular, the surface will be proportional to

as angles of incidence and reflection.ThereforeNow let

The rays of the first group P' Q' R' S' are all reflected twice before passingout of the stone, and make, after the second reflection, an angle of 17°with the vertical (as by eq. (12)). Of the rays of the second group,most are reflected once only (P1 Q1 R1) and make then an angle of 69½° with the vertical. Part of the second group is reflected twice (P3 Q3 R3 S3), and strikes the bezelat 29° to the vertical. This last part will be considered later,and may be neglected for the moment.

For that position E (shown on ), measures scaled off the drawing give

If the ray P Q R was drawn such that M P = M R, then P and R will be the pointsat which the bezels should meet the table. For if P Q be drawn nearer to the centreof the stone, Q R will then meet the bezel, and if P Q be drawn further away,it will meet the opposite bezel upon its entry into the stone and will be deflected.

These measures, worked out in percentage terms of A B, give :--

The bezels have been introduced into the design to disperse the rays which wereoriginally incident from the right upon facet A B. To find the limits of the table,we have therefore to consider the path of the limiting oblique ray. We know that this ray has an angle of incidence of 42½° and an angle of refraction of 16° 19'. Let us draw such a ray P Q: it will be totally reflected along Q R, if we make P Q N = N Q R, where Q N is the normal. Now Q R should meet a bezel.