27 

 HOW TO USE THE THERMOMETER. 



ITH a view of preventing any erroneous readings, I wish to give your 

 readers a few hints, and to enable them to correct their thennometers 

 when out of order. I refer especially to Eutherford'srazwimwrn thermometer. 

 Many persons have put their thermometers out of order by laying them 

 down flat, or by allowing the top end to be lower than the bulb._ The 

 fluid has become separated, and an air bubble has crept into the fluid, which in cold 

 ■weather has receded into the bulb, causing the thermometer to read higher than it 

 should do. Another source of error is when the indicating fluid has, by reason of 

 its having been exposed to the rays of the sun in summer, become condensed in the 

 upper part of the tube, mostly "under the brass loop; when this is the case the 

 thermometer will indicate lower. I have seen as much as 10' of fluid thus con- 

 densed in a colourless state, which is not easily detected. The following simple rules 

 will set ill perfect order any instrument so deranged. 



Take the upper end of the thermometer firmly in the right hand, and swing it 

 violently (bulb downwards) at arm's length ; the chances are that -with half-a-dozen 

 such oscillations the iustrument is put in perfect order. If the contrary be the case, 

 take the bulb end in your right hand, and gently strike the top part of the thermometer 

 on the palm of your left ; continue this, holding the thermometer upright, and all the 

 bubbles will disappear. 



The great risk in carriage in sending an instrument to be adjusted, and the sim- 

 plicity with which the operation is performed, induce me to askvour insertion of the 

 foregoing. I append my name, for, as I am supposed to know something about tlier- 

 mometers, my suggestions may be acted upon by ^^our readers. — H. K^egretti. 



Propagation of Centaurea ragvsixa, caxdidissima, gtmxocarpa, ktc. — 

 These are considered very difiicult to propagate, but like many other subjects that 

 are reputed difiiculties the propagation is a very simple matter when you know lioio 

 to do it. As the Centaureas are the grandest of all the silvery-leaved bedders we pos- 

 sess, and among the most aristocratic plants known, a paragraph on their propagation 

 ■will probably be acceptable both to private growers and to many in the trade. One 

 difficulty is to get shoots long enough for insertion in the soil of the cutting pans. 

 This difficulty is to be got over by taking the plants from the greenhouse to the stove 

 in February ten days before making the cuttings. The heat will lengthen the shoots, 

 and as soon as tbey are long enough to cut take them. The soil for the cutting pans 

 should be peat ivithout the fibre one half, silver-sand one half; mix this thoroughly, 

 and then put it in an oven, and let it hake, hut not hum, till completely dessicated. 

 Dibble in the cuttings and put bell-glasses over; keep on bottom heat ; give no 

 ■water for three weeks, then wet them moderately, and they will throw out shoots 

 immediately, and a week after may be potted in thimbles or thumbs. 



Laxtaxas. — These are so commonly grown as annuals, that few cultivators are 

 aware of the stately dimensions to which they attain when treated as evergreen 

 shrubs, and grown on from year to year. Lantanas are usually regarded as stove 

 plants ; yet most gardeners can grow them well in a warm greenhouse, and durmg 

 the height of summer they may be safely planted in the open ground, or used as 

 pot plants for the decoration of balconies, etc. The soil required is a light and 

 rather peaty mixture ; the exact composition is of no consequence ; half peat and 

 half loam will dj, so wmU a mixture of nice friable yellow loam, with a third part 

 or even half part of leaf-mould. To be well drained is essential ; and while 

 growing they require abundance of water. The principal difficulty appears to be 

 the keeping of Lantanas during winter. What they require is a certain degree of 

 warmth ; if kept too cold, they become mildewed and miserable, and perhaps die 

 at the collar ; but if never in a temperature colder than 40', and averaging not 

 lower than 45\ will take no harm, and it matters not whether the situation be a 

 sunny window or a shelf in a greenhouse, heated with hot-water pipes, tor in truth 

 Lantanas are very accommodating as window plants. The following are six beautiful 

 varieties : — Adolyhe Hioass, gold yellow ; Crocea superha, orange and red, and a 

 capital bedder ; Delicaiissima, pinky-lilac, a good bedder ; FilUoni, rose-violet, 

 vellow centre; Fulgens imitabilis, yellow, cha-.iging to orange-tinted crimson; 

 Monsieur Rendatler, shaded rose and salmon ; Victoria, pure white ; Xanthma 

 superha, yellow and scarlet. 



