4. Fa'i.la.tun, i.e. Watad mafruk followed by two Sabab khafif = the Latin Epitritus secundus (-U- -).

The number of the secondary feet increases to six, for as Nos. 2 and 4 contain two Sabab, they "branch out" into two derived feet each, according to both Sabab or only one changing place with regard to the Watad. They are:

5. Fa.'ilun, i.e. Sabab khafif followed by Watad majmu'= the Latin Creticus (-U-). The primary Fa'u.lun becomes by transposition Lun.fa'u. To bring this into conformity with a current derivative of fa'l, the initial Sabab must be made to contain the first letter of the root, and the Watad the two remaining ones in their proper order. Fa is therefore subst.i.tuted for lun, and 'ilun for fa'u, forming together the above Fa.'ilun.

By similar subst.i.tutions, which it would be tedious to specify in each separate case, Mafa.'i.lun becomes:

6. Mus.taf.'ilun, for 'i.lun.mafa, i.e. two Sabab khafif, followed by Watad majmu' = the Latin Epitritus tertius (- -U-), or:

7. Fa.'ila.tun, for Lun.mafa.'i, i.e. Watad majmu' between two Sabab khafif = the Latin Epitritus secundus (-U- -).

8. Mutafa.'ilun (for 'Alatun.mufa, the reversed Mufa.'alatun), i.e. Fasilah followed by Watad majmu'=the Latin Anapaest succeeded by Iambus (UU-U-). The last two secondary feet are transpositions of No. 4, Fa'i.la.tun, namely:

9. Maf.'u.latu, for La.tun.fa'i, i.e. two Sabab khafif, followed by Watad mafruk = the Latin Epitritus quartus (- - -U).

10. Mus.taf'i.lun, for Tun.fa'i.la, i.e. Watad mafruk between two Sabab khafif=the Latin Epitritus tertius (- -U-).[FN#452]

The "branch"-foot Fa.'ilun (No. 5), like its "root" Fa'u.lun (No.

1), is quinqueliteral. All other feet, primary or secondary, consist necessarily of seven letters, as they contain a triliteral Watad (see supra i. 2) with either two biliteral Sabab khafif (i. 1) or a quadriliteral Fasilah (i. 3). They are, therefore, called Saba'i = seven lettered.

iii. The same principle of the Watad taking precedence over Sabab and Fasilah, rules the arrangement of the Arabic metres, which are divided into five circles (Dawair, pl. of Dairah), so called for reasons presently to be explained. The first is named:

A. Dairat al-Mukhtalif, circle of "the varied" metre, because it is composed of feet of various length, the five-lettered Fa'ulun (supra ii. 1) and the seven-lettered Mafa'ilun (ii. 2) with their secondaries Fa'ilun, Mustaf.'ilun and Fa.'ilatun (ii.

5-7), and it comprises three Buhur or metres (pi. of Bahr, sea), the Tawil, Madid and Basit.

1. Al-Tawil, consisting of twice

Fa'u.lun Mafa.'ilun Fa'u.lun Mafa.'ilun,

the cla.s.sical scheme for which would be

U - - | U - - - | U - - | U - - - |

If we transfer the Watad Fa'u from the beginning of the line to the end, it would read:

Lun.mafa'i Lun.fa'u Lun.mafa'i Lun.fa'u which, after the subst.i.tutions indicated above (ii. 7 and 5), becomes:

2. Al-Madid, consisting of twice

Fa.'ilatun Fa.'ilun Fa.'ilatun Fa.'ilun.

which may be represented by the cla.s.sical scheme

- U - - | - U - | - U - - | - U - |

If again, returning to the Tawil, we make the break after the Watad of the second foot we obtain the line:

'ilun.fa'u. Lum.mafa 'ilun.fa'u Lun.mafa, and as metrically

'ilun.fa'u (two Sabab followed by Watad) and Lun.mafa (one Sabab followed by Watad) are='ilun.mafa and Lun.fa'u respectively, their Taf'il is effected by the same subst.i.tutions as in ii. 5 and 6, and they become:

3. Basit, consisting of twice

Mustaf.'ilun Fa.'ilun Mustaf.'ilun Fa.'ilun,

in conformity with the cla.s.sical scheme:

- - U - | - U - | - - U - | - U - |

Thus one metre evolves from another by a kind of rotation, which suggested to the Prosodists an ingenious device of representing them by circles (hence the name Dairah), round the circ.u.mference of which on the outside the complete Taf'il of the original metre is written, while each moved letter is faced by a small loop, each quiescent by a small vertical stroke[FN#453] inside the circle. Then, in the case of this present Dairat al-Mukhtalif for instance, the loop corresponding to the initial f of the first Fa'ulun is marked as the beginning of the Tawil, that corresponding to its l (of the Sabab fun) as the beginning of the Madid, and that corresponding to the 'Ayn of the next Mafa'ilun as the beginning of the Basit. The same process applies to all the following circles, but our limited s.p.a.ce compels us simply to enumerate them, together with their Buhur, without further reference to the mode of their evolution.

B. Dairat al-Mutalif, circle of "the agreeing" metre, so called because all its feet agree in length, consisting of seven letters each. It contains:

1. Al-Wafir, composed of twice

Mufa.'alatun Mufa.'alatun Mufa.'alatun (ii. 3)

= U - U U - | U - U U - | U - U U - |

where the Iambus in each foot precedes the Anapaest, and its reversal:

2. Al-Kamil, consisting of twice

Mutafa.'ilun Mutafa.'ilun Mutafa.'ilun (ii. 8)

= U U - U - | U U - U - | U U - U - |

where the Anapaest takes the first place in every foot.

C. Dairat al-Mujtalab, circle of "the brought on" metre, so called because its seven-lettered feet are brought on from the first circle.

1. Al-Hazaj, consisting of twice

Mafa.'ilun Mafa.'ilun Mafa.'ilun (ii. 2)

= U - - - | U - - - | U - - - | U - - - |

2. Al-Rajaz, consisting of twice

Mustaf.'ilun Mustaf.'ilun Mustaf.'ilun,

and, in this full form, almost identical with the Iambic Trimeter of the Greek Drama:

- - U - | - - U - | - - U - |

3. Al-Ramal, consisting of twice

Fa.'ilatun Fa.'ilatun Fa.'ilatun,