Reference has been made to the manufacture of condensed milk During the past winter I received a sample of New Zealand condensed milk, which, although perfectly wholesome and agreeable to the taste, was certainly not marketable in England. It was solid and gelatinous, instead of being creamy and liquid. I examined the sample side by side with a sample of the best brand made by the Anglo-Swiss Company. The difference in appearance was most striking, and I took photographs from the microscope, and subsequently obtained a drawing by a competent artist.

It will be noticed that in the Anglo-Swiss sample the sugar-crystals are small and regular, whereas in the New Zealand sample they are large and irregular in size. I have on several occasions been enabled to see the system of milk-condensing in some of them factories of Switzerland, and in the year 1887 I went to that country to obtain some information for the benefit of a large company which is interested in New Zealand, and which had in contemplation the establishment of a condensed-milk factory in the colony. The following are the details of cost of the apparatus required (Swiss-made) :—

Copper vacuum of 5,000 litres capacity, for heating up to 75lb. per square inch, with vacuum-meter, thermometer, and glass gauge to show the level of milk within, with safety-valve, three stop valves for condensing water, three air-taps for double bottom, one air-tap for the vacuum apparatus, £340; a copper elbow for the top of the vacuum, £16; a shutting-off register for milk, steam, and water, £24; a vacuum of 300mm. diameter of piston with 480mm. stroke, sixty revolutions per minute, for driving by belt, with fast and-loose pulley, and injection-cock, £168; cast-iron condenser with injection-pipe, £23; two copper pans for preliminary heating of the milk, each of 1,500 litres capacity, for heating to 75lb. per square inch, with double-bottom stop-valves for steam and condensed water, a safety-valve, discharge-valve, and three air-taps, £180; two cans page 31 with discharge-tap for filling the tins, £16; the cooling apparatus for forty-seven milk-cans, £160; one hundred cans, £112; copper weighing-pan for reception of the milk, £26; two washing-tables with four lever steam-and water-valves, £48; milk-tin-testing apparatus (4) with air-pump, £76. An engine of twelve-to fifteen-horse power is required for this installation, together with two Cornish boilers, each with 60 square metres of heating-surface. The vacuum-pan of 5,000 litres capacity, the size usually adopted, permits of a daily working of 10,000 to 15,000 litres of milk.

For the manufacture of the tins it is necessary to obtain machinery for stamping out the body, the tops and bottoms, and the centre of the lid, as well as to solder the parts together. In the large factories machinery is also used for box-making. In London prices were quoted to me for ready-made tins at the rate of 7s. 6d. per gross in lots of not less than twenty gross. In order to furnish some idea of the cost of manufacturing condensed milk I have prepared the following figures, which are based upon the price of 6½d. per gallon, the price largely paid at some British factories at the time of my investigations, and upon the then price of sugar, 1¾d. per pound. Fine white sugar added at the rate of 10lb. to 100lb. of milk forms a mixture which is condensed until but from 28lb. to 29lb. remains. Of this, 25lb. is used for sale, the residue, which is practically sediment, being given to pigs, for which it is worth at least 1d. per pound. The milk and sugar at the price quoted would cost 6s. 8½d., or about 3¼d. per tin. If we add to this the labour of preparation, the cost is brought up to 3.58d., practically 4d. per tin. Condensed milk can be bought in the English market at from 4d. to 6½d. per tin, the cheaper brands being in all probability made from milk which has been partially skimmed. We have seen the London prices for tins is 5/8d. apiece. This might probably be reduced to ½d. it they were made in the factory, and if tin were obtainable at English prices. In New Zealand the maker of condensed milk has the advantage of being able to purchase his milk at a much lower price than is possible in England, and, indeed, at a lower price than is now paid to the Swiss farmers. On the other hand, I understand that the cost of sugar is considerably higher than it is in this country. In an interview which I had with the director of the Anglo-Swiss Company I learned that in America a drawback is allowed by the Government upon tin and sugar, and, as this company has a factory in the United States, they are consequently enabled to produce condensed milk in that country at a cheaper rate than they are able to do either in England or Switzerland. It is possible that the Government of New Zealand might be induced to assist the condensed-milk industry in a similar manner. In such a case there is no reason why it should not become an important feature in connection with the agriculture of the colony. I have ascertained, by making a calculation based upon the actual quantity of condensed milk made in one large factory, and reckoning the milk at 4½d. per page 32 gallon, the sugar at 1 1/3d. per pound, the tins at ½d. each, and the residue at 1d. per pound, that each tin could be made at a cost of 2.88d. without the labour. In this calculation the milk is supposed to contain 12.90 per cent, of total solids. The following table shows the proportion of the various constituents which are found in 100lb. of milk and 10lb. of sugar after condensing :—

	Per Cent.
Water	6.50
Cane-sugar	10.00
Milk-sugar	4.00
Fat	3.60
Casein	4.00
Ash	0.50
	28.60

The soldering-machine costs £15 in London, and I am informed that a smart girl can solder fifteen gross of tins per day. The solder used in the process costs 7½d. per gross of tins. The prices paid for milk at the Aylesbury Condensing Factory were 6½d. for the six summer months, 7½d. for two months, 8½d. for two months, 9½d. for one month, and 10½d. for one month. These prices, I believe, have been recently slightly reduced.

Norwegian Milk.

I find by reference to official Norwegian statistics that the price of condensed milk in Norway has fallen from 0.90 crown (10.65d.) in 1882 to 0.75 crown (9¾d.) in 1886 per kilogramme. Some idea of the quality of Norwegian milk may be obtained from the following figures, which were kindly sent me by Mr. Tobiesen, one of the chief Government officials in agricultural matters. Upon one farm the milk varied in quantity from 10,800 litres in July to 27,100 litres in May. The lowest quantity of milk required to make a pound of butter was 22.59lb. in October, and the highest quantity was 26-20lb. in August. In another case the page 33 average ratio was 24.77lb.; in September it took 21.52lb., and in December 26.92lb.

Milk-contract Stipulations.

Whatever line of business is conducted at a factory or creamery, certain stipulations should be made with the farmers; and, if contracts are made for the supply of milk at a given price, it would be convenient that these stipulations should be included in the form of contract. Each contributor of milk should be required to maintain milk of a certain quality, to guarantee its purity and wholesomeness, to undertake that no milk should be sent from cows which have calved within seven days, or from cows which are unwholesome or suffering from any affection of the udder; that he will at once apprise the manager of the factory in case of disease breaking out among his cattle, or among his own family or the families of his employès; that he will supply his milk in absolutely clean utensils; that he will use foods which are approved by the manager; that he will give free admission to any person authorised to inspect his farm or cattle on behalf of the factory; that he will deliver his milk by a certain hour, as may be determined (and in butter-and-cheese factories that he will repurchase the whey or the skim-milk at such a price and in such quantities as may be arranged between himself and the manager); and that he will sell his milk by weight.

Pig-feeding.

There are few factories where the whole of the skim-milk is taken back by the farmers, and, as the manufacture of skim-milk cheese is not a business which can be recommended for extension in the colony, it appears to me to be necessary that a piggery should be established in connection with each factory, and it may ultimately become a question whether it may not be advisable to establish bacon-factories, which are most successful in Ireland, and which are extending in the dairy districts of Denmark and in the north of Germany, whatever may be done in the future, there is little doubt that it will be found most advantageous to employ the best breeds of British pigs, such as the Large and Middle White Yorkshire, the Berkshire, and the Tamworth, for the improvement of the swine of the colony. I have endeavoured to show in "The Book of the Pig" how pigs may be bred and fed with economy, and, as there can be little doubt that for conversion into bacon the half-bred pig is one of the best, if not the best, animals which can be employed, it will be found necessary to select one or more of the pure breeds for the purpose of regular crossing. The whey obtained from a cheese-factory is a valuable food for swine, and in England is estimated to be worth at the rate of £1 per cow per annum. Skim-milk is of much greater value, and in pork-production is probably worth from 1d. to 1¼d. per gallon, in England. Combined with maize it is one of the best foods which can be given to pigs. I must not, however, omit to mention that page 34 the whey which has passed from the cheese-vats usually furnishes a large percentage of butter, which should be extracted as early as possible. If the whey is allowed to become sour before the butter-fat is removed from it, the butter will not be worth so much per pound, hence the necessity of extracting it while the whey is sweet. I have made some experiments in this direction by passing the whey through a centrifugal machine, and the results have been sufficiently good to warrant further and more extended tests being made. It is possible to make whey-butter almost equal in delicacy of flavour to that obtained in the ordinary way.