The reproduction of tsetse-flies is highly remarkable; instead of laying eggs or being ovovivi parous the females deposit at intervals of about a fortnight or three weeks a single full-grown larva, which forthwith buries itself in the ground to a depth of several centi metres, and assumes the pupal state.

Thus the **centi-ampere** balance ranges from i to ioo **centi-amperes**, the deci-ampere balance from i to ioo deci-amperes, the ampere balance from i to ioo amperes, the deka-ampere balance from i to ioo amperes, the hecto-ampere balance from 6 to 600 amperes, and the kilo-ampere balance from ioo to 2500 amperes.

The continental engineer prefers kilogrammetres per kilogramme-degree-centi grade.

The prefixes for multiplication by io, io 2, io 3 and Io 4 are deca-, hecto-, kilo- and myria-, and those for division by io, io 2 and io 3 are deci-, centi- and milli-; the former being derived from Greek, and the latter from Latin.