There are con siderable irregularities, how ever, in this respect, and the number of leaves in different whorls is not always uniform, as may be seen in Lysimachia
To widen it more abruptly would indeed increase the volume of the furnace, but would probably lead to grave irregularities in the distribution of the gas and charge, and hence in the working of the furnace.
The special conditions of the blast-furnace actually exaggerate the saving due to this widening of the available temperature-margin, and beyond this drying the blast does great good by preventing the serious irregularities in working the furnace caused by changes in the humidity of the air with varying weather.
The obstacle is that, owing to unavoidable irregularities in the blast-furnace process, the siliconand sulphur-content of the cast iron vary to a degree and with an abruptness which are inconvenient for any conversion process and intolerable for the Bessemer process.
And it must be admitted that there are also many cases, some of them caused by irregularities of writing, modification of spelling by decay, and by a probable use of prefixes still unascertained, which also resist explanation, though the account just given stands good whatever solution the question of prefixes may receive in future.