The Practical Miner's Guide: A Treatise on Mine EngineeringD. Appleton & Company, 1860 |
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Σελίδα 60
... iron pins let into stone . These points , being marked on the plan , will form a datum north and south line , with which at any time a dialler can compare his instruments , and make the necessary allowance for change of variation . If ...
... iron pins let into stone . These points , being marked on the plan , will form a datum north and south line , with which at any time a dialler can compare his instruments , and make the necessary allowance for change of variation . If ...
Σελίδα 62
... iron , which always abounds in the vicinity of a mine , be done away . What is said of Mercator's sailing may , in the chief respect , be applied to horizontal dialling , viz .: " It is the art of finding on a plane surface the motion ...
... iron , which always abounds in the vicinity of a mine , be done away . What is said of Mercator's sailing may , in the chief respect , be applied to horizontal dialling , viz .: " It is the art of finding on a plane surface the motion ...
Σελίδα 76
... iron . rendered useless , and he has happily succeeded . This method of surveying cannot be performed with the com- mon dial ; but the best circumferentors are now made with an external graduation and vernier scale , on the theodolite ...
... iron . rendered useless , and he has happily succeeded . This method of surveying cannot be performed with the com- mon dial ; but the best circumferentors are now made with an external graduation and vernier scale , on the theodolite ...
Σελίδα 77
... iron for the first draft ; and taking the observation with the needle , we find the north point ( a right - hand dial ) stand at 1761 ° ; we then fix the outer circle with the vernier precisely at the same point , and THE PRACTICAL ...
... iron for the first draft ; and taking the observation with the needle , we find the north point ( a right - hand dial ) stand at 1761 ° ; we then fix the outer circle with the vernier precisely at the same point , and THE PRACTICAL ...
Σελίδα 78
... iron pumps ; a job that has often baffled the skill and ingenuity of diallers , and occa- sioned numerous and most serious errors . The operation may be performed thus : -Suppose we are in the 60 fathom level , and from thence to the ...
... iron pumps ; a job that has often baffled the skill and ingenuity of diallers , and occa- sioned numerous and most serious errors . The operation may be performed thus : -Suppose we are in the 60 fathom level , and from thence to the ...
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The Practical Miner's Guide: A Treatise on Mine Engineering; Comprising a ... John Budge Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2017 |
The Practical Miner's Guide: A Treatise on Mine Engineering John Budge Δεν υπάρχει διαθέσιμη προεπισκόπηση - 2019 |
Συχνά εμφανιζόμενοι όροι και φράσεις
adit air currents angle of acclivity Answer art of dialling ascer assay base and perpendicular bearing boring carbonic acid coal collieries column Comp consequently course cross-cut cylinder Davy lamp Decimals degrees depth diagonal shaft dial dialler dialling diameter direction distance ditto draft drift dwts EXAMPLE explosion fath fathom level feet 8 inches fire-damp foot furnace given angle given side Given the angle goaves hemp horizontal hypothenuse inflammable inflammable gas instrument iron lamp length lode measure method miner mines MUESELER lamp multiply observed operation Perp perpendicular shaft Plane sailing practice protractor quantity of air radius required to know right angles rods second table shaft A B specific gravity stand steam subtract sunk surface survey temperature tion triangle trigonometrical underground underlay upcast shaft velocity ventilation vernier scale weight winze wire gauze wire rope yarns
Δημοφιλή αποσπάσματα
Σελίδα 186 - Through the interior of the tube a column of water is sent down to the bottom of the boreholes, which water, rising in the annular space between the exterior of the hollow boring rod and the sides of the bore-hole, creates an ascending current which carries up the triturated soil : the boring tube is then worked like an ordinary boring rod ; and as the material is acted upon by the tool at the lower end, it is immediately carried up to the top of the bore-hole by the ascending current of water. It...
Σελίδα 7 - Multiply the decimal by the number of parts in the next less denomination, and cut oft' so many places for a remainder, to the right hand, as there are places in the given decimal. 2. Multiply the remainder by the...
Σελίδα 172 - There is another class of injuries resulting from defective ventilation to which miners are exposed. The circumstances producing these injuries are slow in operation, and from their effects being disease, and not immediate and sudden death, their existtence has been little considered.
Σελίδα 186 - ... the strata which have to be encountered. The diameter of the tool is larger than the diameter of the tubular rod, in order to form around it an annular space through which the water and the excavated material may rise up. The upper end of the hollow rod is connected with a forcepump by jointed or flexible tubes, which will follow the descending movement of the boring tube for an extent of some yards. This boring tube may be either worked by a rotary movement with a turning handle, or by percussion...
Σελίδα 172 - These effects are the result of an inadequate supply of air, which thus becomes vitiated and unfit for breathing, on account of its having lost its due proportion of oxygen, which is replaced by the formation of carbonic acid. This gas has its sources...
Σελίδα 66 - AC in d and e; then take the distance ed in your compasses, and setting one foot on the brass pin at the beginning of the chords on your scale, observe how many degrees the other foot reaches to, which will be 4° 15
Σελίδα 172 - ... which has become vitiated and unfit for breathing, on account of its having lost its due proportion of oxygen, which is replaced by the formation of carbonic acid. This gas has its sources in respiration, the lights of the mine, the decomposition of small coal in the goaves (cavities of the roof), and of timber in the workings.
Σελίδα 13 - The sum of the three angles of every plane triangle being equal to half a circle, or 180 degrees, it therefore follows that if either acute angle, in such triangle, be taken from 90°, the remainder will be the other acute angle, or the complement. The supplement of any angle is what that angle wants of 180°: hence the supplement of any one angle is always equal to the sum of the other two. A few other properties of right-angled triangles may be worthy of notice, viz.: when the angle opposite the...
Σελίδα 63 - ... multiply them respectively by the length of the hypothenuse, reduced into fathoms and parts (if any), and place them in their proper positions until the whole has been calculated ; then take the sum of the bases north and south one from the other, and the sum of the perpendiculars east and west one from the other ; the perpendicular remainders will show the east and west line, and the bases the distance the dialling has extended north or south of that line. The work is now brought to that case...
Σελίδα 175 - ... which the apertures filled more space than the cooling surface, so as to be permeable to air and light, offered a perfect barrier to explosion, from the force being divided between, and the heat communicated to an immense number of surfaces.