and this is done very easily. A boy turns the handle intended for the escape of the dough, and in doing so, presents a small orifice through which it is forced with such power, that, on entering a large tin tube made of a suitable size, it fills the whole space, and being still farther pushed forward, is allowed to fall into a dish prepared to receive it, and is then cut off with a knife. Thus, one boy works the key to permit the dough to escape, another holds up a wooden tray made to hold exactly 2 lb., cuts off the dough, hands it to a third boy, who weighs it, tray and all, passing it to a fourth boy, who transfers the small loaf into a tin pan ready to be placed in the oven. This goes on with more rapidity than I can describe; but it may be curious to know the precise time occupied in the whole operation.

The flour and salt are placed in the mixer in two minutes; the air is exhausted from this vessel in four; carbonic acid gas is pumped in ten; the materials are all mixed, and the dough perfectly formed in eight. Thus in twenty-four minutes, we have a sack of flour converted into dough, suitable for placing in the oven; while if we allow one hour for the time the bread remains there to be fired, we have some idea of the very rapid manner in which bread may be made by this process. I may here draw attention to the fact, that in all the various stages, the hand never touches the dough until it has become a loaf, and is ready for use. I was much struck with the kind of ovens in use at this manufactory. They are named travelling ovens, and are so constructed, that the floor of each shall be formed of moveable iron plates, of such a size, as will hold twelve loaves in a row, while the length is so considerable, that each will contain the produce of two sacks of flour, or about 400 half quartern loaves. The movement of the floor is so regulated, that from the time the dough is placed on the first set, until it passes the whole length of the oven, one hour elapses, and this gives the proper time for the bread to be baked, so that while the loaves are tumbling out baked at one end, there is a constant supply of fresh dough put in at the other; and thus a constant circulation is kept up, as long as the dough continues to be made. As supplementary to those travelling, there are perpetual ovens also in use. These receive

this appellation in consequence of the fire being placed at the back, and are thus fed and supplied with coal, without in any way disturbing what may be in the oven. Now I witnessed the dough after being weighed, carried to these ovens and placed there, just as is customary in the ordinary bake-house. Two machines are generally placed together, and the staff required to work these consists of one foreman, two oven men, and nine boys. These will work about two sacks of flour every hour. At present the consumpt is forty sacks every night, but it is said they were at the time I made my visit making less than the average, and they expected soon to be converting double the number of sacks of flour per night into bread. The first quantity would give roughly, as the making per night, 4000 whole or 8000 half loaves.

The bread produced by this process is very pleasant and sweet, and certainly approaches more nearly to that baked with German yeast than any I have seen. Already the licence to work the patent in Scotland has been secured, and if Messrs P. F. & Co. are successful, it is expected that factories will soon be established in some of our largest towns. It must be evident from what has been stated, that the patent system just described is only admissible on the large scale, although, I believe, the patentee is sanguine, that even ordinary bakers may yet employ his apparatus, as he contemplates having them made of such a size, as will enable them to be worked by hand power. One objection by many to this bread is, that it is still a shade higher in price than the ordinary loaf, to the extent of from a farthing to a half-penny on each. It occurred to me that with such rapidity of manufacture, the objectionable night-work might be got quit of altogether; and I said so, but was told that their customers would have new bread in the morning, and therefore they had to bake at night, make the bread ready early in the morning, pack into vans, and despatch these-to the number of fifteen-round the various districts requiring supplies, so as to be ready for early breakfast. Indeed, this is one of the reasons why the price of this bread is at present higher, viz. the great expense in sending it so far away after it has been prepared.

One difficulty still remains to be overcome in connection

with the manufacture, and that is to get rid of sulphuric acid in the preparation of carbonic acid gas. This, the company are struggling to do, having the idea, that if the common chalk can only be heated to a sufficiently high temperature, chemical affinity will be overcome, and the gaseous compound set at liberty. The partners are sanguine of success, the only existing obstacle being the difficulty of getting materials of which to make retorts that will stand the excessive heat. If they accomplish this, there will be a saving of at least 3s. on each sack of flour.

Two remarks more, and I finish this part of my subject: and first, in consequence of the non-abstraction of any portion of starch to produce the fermentive action, so constantly followed in all our bakeries, it was imagined and believed, that there would be a positive saving of flour, to the extent of at least 10 per cent. This, I understood, was Dr Dauglish's own idea. All very well in theory, but when reduced to practice found to be erroneous. The real saving-for that there is a saving is undoubted—amounts to 3, and actually never exceeds 31 per cent.

The other remark is, that medical men are still somewhat divided in opinion regarding the merits of this new bread for general use. Some laud it very highly, and go the length of stating, that it will cure weak digestion, and thus give relief in all dyspeptic cases. Others allege and maintain, that it is not only indigestible, but that bad effects are sure to follow, in cases of weak or impaired digestion. Thus the famous Dr Letheby has declared that all kinds of unfermented bread, Dr Dauglish's among the number, are more or less liable to produce gastric derangement. Mr Lobb, on the other hand, declares, that to some, fermented bread was all but poisonous, and that from personal experience the use of the aerated bread gave the most wholesome results. Dr Lankester is much in favour of the new bread. Without pursuing this part of my subject farther, I may just observe, that it is not alone on this point that "doctors differ;" while doubtless for a time, and indeed as long as aerated bread is made, there will be found some high in its praise, while others will give a preference to the old loaf. The patent bread will certainly have one advantage, viz. it will never be sour, and be always uniform.

I fear I have exhausted your patience by the preceding remarks in connection with yeast and bread-making; but the real interest attached to any information connected with the manufacture of an article of such importance, not to any one community alone, but to the whole human race, must plead my apology. I would only add, that from the amount of success which has already attended Dr Dauglish's patent for the production of bread, it would almost appear as if the appliances of chemical knowledge and mechanical skill, were about to create a favourable change in the production of what is correctly called the staff of life. With the probability of solid yeast being made in this country, capable of producing bread by fermentation in from one to two hours, and the Aerating machine turning out prepared dough in twenty-four minutes, what changes may not be fearlessly prognosticated! Iron in many cases, both on the Continent and at home, is now doing what the muscles of the arms and legs have been called upon for centuries to do, while steam power has been seized, and compelled to mix, manufacture, cut, and even weigh dough suitable for bread. In all sincerity, let me express the hope, that ere long, by continued exertion and enterprise, such improvements will be effected in the mode of manufacturing our daily bread, that the knell of utter annihilation may be rung, for the removal of such miserable holes and dens, as we know to exist in many large cities and small towns, where men toil and work from early morning till far advanced in the afternoon, in places called bakehouses. As a rule, far below the surface of the ground, low-roofed, badly ventilated, and as badly lighted-gas burning most of the day -the air at a high temperature and otherwise vitiated, men are found at work, until too frequently the whole animal system receives a shock, too great for flesh and blood to stand; till at last many fall victims, or dwindle prematurely into such a state of health as precludes their following out any other avocation, thus leaving them too often dependent upon the charity of others. I do not say that the aerated bread system is to be a panacea for these evils, but I have often thought that, in the preparation of dough, much that is at present objectionable might be removed, labour lessened, and compara

tive health preserved, while I am convinced, that the production and use of German yeast, would be one step to the abandonment of night and Sabbath-day labour, as at present existing in our bakeries.

In conclusion, having now, I hope, satisfactorily shown that solid yeast CAN be prepared here, of as good quality in every respect, as that imported from abroad; and having also referred to the difficulties in the way of at once entering upon its manufacture as an article of commerce, I may be allowed to say, that in the event of the Excise still more relaxing their laws, and allowing the distillers to remove all the yeast they can skim from their vats, and if it shall be found that the steady use of certain grain will afford a margin of profit to the manufacturer, then I have little doubt we shall very soon prevent large sums of money leaving this country, and find Scotland, already famous over the whole world for many of its manufactured articles, taking the lead in the production of a solid yeast of such quality and make as will not only give entire satisfaction to the present dealer, but also open up a new trade, by inducing many who have not hitherto used the article to test its merits for baking purposes, and become convinced of its superiority over the barm at present used.

Description of an Improved Turret-clock Hammer. By ROBERT J. WOOD, Clockmaker, 9 Leith Street Terrace, Edinburgh.*

Before proceeding to describe the construction of the turretclock hammer, which I shall have the honour of submitting to your notice this evening, I trust it will not be considered out of place to refer briefly to the ordinary manner of constructing such hammers, for the purpose of pointing out more clearly the defects of the ordinary construction, and the precise nature of the improvements which I have to propose.

A turret-clock hammer, as usually made, consists generally

* Read before the Society, and instrument exhibited in action, 11th February