§ MR. GRAY
asked the President of the Board of Trade, with reference to the statement of the Elder Brethren of the Trinity House that several valuable lenses have been cracked by the heat of the gas burners, Whether this statement has been absolutely denied; whether the makers of the lenses have stated that they can sustain with perfect safety a vastly greater temperature than the 314 degrees mentioned by the Elder Brethren; whether since the reply of the Right honourable gentleman has been made public, the inventor of the gas system has written to the Elder Brethren offering to guarantee the safety of the lenses from injury by heat during the trial of the double triform arrangement; whether it is the fact, as implied by the letter of the Elder Brethren, that Dr. Ball has changed his mind, and that, although he resigned his seat on the Illuminants Committee because they would not allow the double triform to be used in the experiments, he is now satisfied to have it excluded from the trials; whether the inventor of the gas system has repeatedly urged that the full power of gaslight for penetrating fogs could not be shown unless the double triform were tested, and that this method of burning gas would have a much greater effect in illuminating fog than any other lighthouse illuminant, and whether the rea- 826 sons given by the Right honourable gentleman are sufficient to warrant his refusal to test it; whether, on further inquiry, he is still convinced that the double triform arrangement would work as well with oil as with gas, and in supposing that, a comparison having been made between three gas lights and three oil lights, the same comparison would hold good in the case of the double triform; whether the Elder Brethren, with full cognizance of the lenses having cracked, applied for a tender for the erection of the double triform; and, whether the objection to permit its use lies in the reluctance of the Board of Trade to incur the expenditure necessary for this experiment?
§ MR. CHAMBERLAIN
I have no personal knowledge of the matter referred to; but I have received the following letter from the Trinity House:—The statement that lenses have been damaged through heat has been denied but not disproved; the cracked lenses are still to be seen in their places. No statement that a higher temperature than 314 degrees could be sustained with safety has been received by the Trinity House from the makers of the lenses (the temperature, as previously stated, was 350 degrees; it has been as high as 374 degrees). The inventor has written an offer to guarantee the safety of the lenses while under trial in double-triform, but limited to what is proved to be injury by heat. The Elder Brethren have received no intimation whatever from Dr. Ball as to the proposal for double-triform lights; but they are assured that in all that pertains to the experiments, they are in perfect accord with the Commissioners of Irish Lights, to whom that gentleman is scientific adviser. The inventor has urged the trial of double-triform apparatus, as being, in his opinion, more effective in fog than other methods: the reasons for not testing it appear to be sufficient to the practical and scientific men engaged in the inquiry. The Elder Brethren applied to the inventor for practical details of the double-triform arrangement, and for a statement of the expense. A partial statement of expense was rendered, but practical details were not given, and the Trinity House are unable therefore to judge of its convenience relatively with oil. There seems no reason to doubt that comparisons between three gas lights and three oil lights would hold good in the case of double-triform gas and double-triform oil. Other objections besides expense have influenced the Trinity House in refraining from trying it.To this statement of the Elder Brethren I have only to add that there has not only been no reluctance whatever on the part of the Board of Trade to sanction any expenditure which the Trinity House may think necessary to carry out those experiments satisfactorily, but that the 827 expenses in connection with the experiments up to the end of November last had amounted to upwards of £10,000.