The mean result of the best determinations shows that when a current of one ampere is passed for one second, a mass of silver is deposited equal to o **ooi** i 18 gramme.

R is bounded by the basal pinacoid c (**ooi**) parallel to which is the perfect cleavage, the clinopinacoid b ((D10) parallel to the plane of symmetry, and the pyramids m (221) and o (112).

The value of the constant / 7 ranges in different metals from about o **ooI** to 0.04; in soft iron and steel it is said to be generally not far from 0.002.

But the Benedictines, whose settlement in Hungary dates from the establishment of their monastery at Pannonhalma (c. 1 **ooi**), were the chief pioneers.

Hence, in order that this zone may be perfectly formed, there should be no error in the circumference of the order of **ooi** cm.

Acetylene tetrabromide, C 2 H 2 Br 4, which is very conveniently prepared by passing acetylene into cooled bromine, has a density of 3 **ooi** at 6° C. It is highly convenient, since it is colourless, odourless, very stable and easily mobile.

An essential accompaniment therefore of the potentiometer is a series of standard low resistances, say of o 1, o oi, o **ooi** ohm, and also a series of higher resistances divided into known fractions.

Of factors of the form I + I r n) to the construction of logarithms, and calculated a table of logarithms of factors of the form i +( **ooi**) r n to 24 places.

000007 (6) I (**ooI**)5602 1 (001) 2 598 (7) i (o00)6412 i (**ooi**) 3 780 (8) I (o01)7340 Taking the logarithms from Gray's tables we obtain the required logarithm by addition as follows: In Shortrede's Tables there are tables of logarithms and factors of the form i = (oi) r n to 16 places and of the form i & (.

In size their cells are commonly about o **ooi** mm.