Milk, cheese, and butter : a practical handbook on their properties and the processes of their production, including a chapter on cream and the methods of its separation from milk / by John Oliver.

  • Oliver, John (Writer on dairy products)
Date:
1894
Catalogue details

Licence: Public Domain Mark

Credit: Milk, cheese, and butter : a practical handbook on their properties and the processes of their production, including a chapter on cream and the methods of its separation from milk / by John Oliver. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    cotton which suck up water from a cup (c) below. The evaporation goes on at a rate dependent on the dryness of the air; and according to the quickness with which the moisture drys off from the bulb, so is the cold and the variation of the mercury. There is therefore generally some difference between the temperatures shown by the two thermometers, and, this being observ'ed, it can be known by reference to the table below how much moisture is m the aii, the largest amount which it can carry being described as loo degrees of humidity. Temperature by dry bulb Difference between thermometers. thermometer. 2* 4 6” 8° Degs. Degrees of humidity. 40 84 70 58 47 42 84 71 59 49 44 85 72 60 50 46 85 73 61 51 48 86 73 62 52 50 86 74 63 53 52 86 74 64 54 54 86 74 64 55 56 87 75 65 56 58 87 76 66 57 60 88 76 66 58 62 88 77 67 58 64 88 77 67 59 66 88 78 68 60 68 88 78 68 60 70 88 78 69 61 72 89 79 69 61 74 89 79 70 62 76 89 79 71 63 78 89 79 71 63 80 90 80 71 63 Example.—If the dry bulb shows a temperature of 62° and the wet one 58°, the difference is 4°, and by looking in the second column opposite the 62° (dry bulb) it will be seen that there are 77° of moisture present. In order to real usefulness such an instrument should be kept in a fairly sheltered spot, and out of the sun’s rays. The quantity of moisture which the air can carry depends on its temperature—the higher this is, the more it can hold. So at a high temperature the moisture may be considerable though unnoticed ; but if the air gets colder, as after sunset, its ability to hold moisture decreases, and whatever it can no longer carry will be deposited as