[9] Repository of Arts, Vol. I, p. 86.
If these circumstances be attended to, three candles of any size thus prepared, last as long as four of the same size manufactured in the common way. The light which they afford is superior and more steady than the light of common candles; and lastly, candles made in this manner, whether of wax, spermaceti, or tallow, do not require to be snuffed as often. Besides all this, they flame much less, and are consequently better for writing, reading, working and drawing, than candles made by the common method.
The following observations will enable any person who is willing to try the candles manufactured according to Lord Stanhope’s plan, to ascertain the real value of the improvements suggested by his Lordship. It shews also the result of some experiments, made to ascertain the expence of burning oil in lamps with wicks of various sizes.
A taper lamp, with eight threads of cotton, will consume in one hour 225⁄1000 oz. of spermaceti oil: at six shillings per gallon, the expence of burning twelve hours is 13.71 farthings.
At seven shillings, it is 15.995 farthings.
At eight shillings, it is 18.280 farthings.
N. B. This gives as good a light as tallow candles of eight and ten in the pound. This lamp seldom wants snuffing, and casts a steady and strong light.
A taper, chamber, or watch lamp, with four ordinary threads of cotton in the wick, consumes 1.664 oz. of spermaceti oil in one hour: the oil at seven shillings per gallon, the expence of burning twelve hours, 7.02 farthings.
At eight shillings, it is 8.022 farthings.