It is necessary that care be taken to regulate the charge with utmost nicety, in order to give the requisite degree of energy. Too much violence in the expulsion will cause the star to be extinguished by the swiftness of its flight through the air, while a lack of velocity will result in the star's dropping earthward immediately. Attention should be given also to the amount of the composition between the stars, since carelessness in this particular might result in setting off two stars at the same time. Any lack in due compression of the composition may have a like result. The minimum height for each charge between stars, after adequate ramming, should never be less than three times the interior diameter of the case.

Roman candles are sometimes equipped with globes of fire in place of the stars. These, in their passage through the air after their emergence from the case, leave behind them a long trail of sparks.

The composition employed for making such globes of fire is as follows:

Powder......................

32

Niter..........................

8

Sulphur.....................

1

Charcoal (hard wood)..........................

6

The composition used for loading Roman candles is the same whether they carry the usual stars or the globes of fire. For the candles of small caliber, either of the two formulas following may be employed:

Powder .......................................

16

Charcoal ..........................................

4

Powder ...................................

16

Niter ........................................

1

Charcoal .......................................

4

For large candles, the following formulas:

Powder........................

16

Niter..................

4

Sulphur.......................

1

Charcoal.................................

7

Powder.....................

4

Niter..................

18

Sulphur.....................

6

Charcoal.......................

7

Niter..................

13

Sulphur................

5

Charcoal......................

2

Sometimes the container is given a funnel shape, either larger or smaller, and is thus made to serve as a miniature mortar for the discharge of stars or globes or small grenades. The composition used in such pieces is the same as that given above.